United States Court of Appeals
                        FOR THE EIGHTH CIRCUIT
                                ___________

                             Nos. 08-1701/1789
                               ___________

PFS Distribution Company; Pilgrim’s   *
Pride Corporation,                    *
                                      *
      Appellants/Cross-Appellees,     *
                                      *
     v.                               *
                                      *
Darrell Raduechel; Barry Spain,       *
                                      *
      Appellees/Cross-Appellants,     * Appeal from the United States
                                      * District Court for the
Richard R. Donohue; Theobald          * Southern District of Iowa.
Donohue & Thompson, P.C.;             *
MidWestOne Bank and Trust; Steven *
P. Hicks,                             *
                                      *
      Appellees/Defendants,           *
                                      *
John Pothoven; D&B Solutions, Inc.,   *
                                      *
      Defendants.                     *
                                 ___________

                          Submitted: April 15, 2009
                             Filed: July 28, 2009
                              ___________

Before WOLLMAN, BYE, and RILEY, Circuit Judges.
                           ___________

RILEY, Circuit Judge.
       PFS Distribution Company (PFS Distribution) and Pilgrim’s Pride Corporation
(Pilgrim’s Pride) (collectively, PFS) sued Darrell Raduechel (Raduechel) and Barry
Spain (Spain) for breach of fiduciary duties and copyright infringement in connection
with the formation and operation of Raduechel’s and Spain’s company, D&B
Solutions, Inc. (D&B Solutions). PFS also sued Raduechel; Spain; D&B Solutions;
John Pothoven (Pothoven); Richard Donohue (Donohue) and Theobald Donohue &
Thompson, P.C. (TD&T) (collectively, Accounting Defendants); and Steven Hicks
(Hicks) and MidWestOne Bank and Trust (MidWestOne) (collectively, Banking
Defendants) for civil conspiracy, constructive trust and unjust enrichment,
misappropriation of trade secrets, and aiding and abetting. D&B Solutions was also
added to PFS’s copyright infringement claim. Raduechel counterclaimed against PFS
for payment of a salary bonus.

       The district court1 dismissed Raduechel’s counterclaim, and granted summary
judgment to PFS on the issue of Raduechel’s and Spain’s liability for breach of
fiduciary duties and misappropriation of trade secrets. The district court left for trial
the remaining claims, as well as the issues of causation and damages for Raduechel’s
and Spain’s breach of fiduciary duties and misappropriation of trade secrets. A jury
returned a verdict in favor of all defendants on all of PFS’s remaining claims. PFS
then moved for equitable relief and a new trial. The district court denied both
motions.

        PFS now challenges the district court’s (1) denial of PFS’s motion for a new
trial; (2) jury instructions on the civil conspiracy, and aiding and abetting claims;
(3) expert witness rulings; and (4) denial of equitable relief. Raduechel cross appeals
the district court’s dismissal of his counterclaim, and Raduechel and Spain challenge
the district court’s summary judgment ruling. We affirm.


      1
      The Honorable Ronald E. Longstaff, United States District Judge for the
Southern District of Iowa.

                                          -2-
I.    BACKGROUND
      PFS owned and operated a food distribution center in Oskaloosa, Iowa (PFS
Oskaloosa). PFS Oskaloosa was originally owned by a private individual, and was
bought by ConAgra Poultry Company (ConAgra Poultry) in 1975. In November
2003, Pilgrim’s Pride bought ConAgra Poultry and acquired PFS Oskaloosa.

       Raduechel began working at PFS Oskaloosa in 1979, and became general
manager around 1991. Spain began working at PFS Oskaloosa in 1987, and was
promoted to sales manager in 1996 or 1997. While Raduechel and Spain worked at
PFS Oskaloosa, two of PFS Oskaloosa’s largest customers for poultry sales were
Affiliated Foods (Affiliated) and Fareway Stores (Fareway). Raduechel handled all
sales to Affiliated, and Spain handled all sales to Fareway.

       When Pilgrim’s Pride acquired ConAgra Poultry, Pilgrim’s Pride assumed
Raduechel’s compensation agreement with ConAgra Poultry, which included a base
salary and an incentive plan. The incentive plan provided Raduechel would receive
a bonus in an amount tied to a percentage of PFS Oskaloosa’s profits, but also
included a provision that allowed reduction of the bonus, down to zero in “extreme
conditions,” if Raduechel’s “general job performance [was] unsatisfactory, or
[Raduechel’s] managerial attitude [was] not in the best interest of the Company.”
Under the incentive plan, Raduechel’s 2003 salary was approximately
$295,000—$45,000 in base salary and approximately $250,000 in bonus.
Raduechel’s compensation agreement was effective until May 30, 2004.

      In December 2003, Raduechel attended a PFS managers meeting in Dallas,
Texas. Although compensation was not formally discussed at the meeting, Raduechel
became concerned that his compensation and business at PFS Oskaloosa would be
reduced. Raduechel, however, left the meeting thinking PFS would have a proposed
compensation package for him by the end of January 2004.



                                       -3-
      Raduechel told Spain about the concerns Raduechel was having regarding
potential compensation and business reduction at PFS Oskaloosa. Raduechel and
Spain began to formulate a “Plan B” in the event “things [did not] work out” at PFS
Oskaloosa. “Plan B” entailed Raduechel and Spain starting their own distribution
company, D&B Solutions, to compete with PFS Oskaloosa.

       In late January 2004, Raduechel and Spain met with Pothoven at MidwestOne
to discuss financing for D&B Solutions. Pothoven advised Raduechel and Spain to
create a business plan, and Pothoven recommended several accountants to assist
Raduechel and Spain. Raduechel and Spain then contacted Donohue at TD&T, and
met or corresponded with Donohue several times during late January and early
February 2004 to discuss and prepare a business plan. During one of the meetings,
Raduechel and Spain gave Donohue financial documents from PFS Oskaloosa. Upon
seeing the documents, Donohue expressed concern that the documents were
confidential, and told Raduechel and Spain to seek legal advice regarding the
documents. Although Donohue inadvertently retained the documents, neither
Raduechel, Spain, nor Donohue used the documents or showed them to anyone after
the documents were initially disclosed.

      In early March 2004, Bobby Matkin (Matkin), a PFS executive, visited PFS
Oskaloosa. During the visit, Matkin told Raduechel that PFS did not yet have a
proposed compensation package for Raduechel. Raduechel was told a proposed
compensation package would be provided to him by April 1, 2004. Raduechel
became frustrated, and continued to work on financing for D&B Solutions at
MidWestOne with Hicks. PFS did not provide Raduechel with a proposed
compensation package on April 1, 2004.

      On May 21, 2004, MidWestOne extended a line of credit, a real estate loan, and
a commitment on a letter of credit to Raduechel and Spain for operation of D&B
Solutions. Around May 26, 2004, Matkin provided Raduechel with a proposed

                                        -4-
compensation agreement. The agreement provided for a base salary of $150,000 and
required Raduechel to manage both PFS Oskaloosa and PFS’s Green Bay office.
Raduechel rejected the offer. Matkin then offered Raduechel a base salary of
$150,000 to manage only PFS Oskaloosa. Raduechel rejected Matkin’s amended
offer, and resigned from PFS Oskaloosa on June 7, 2004.

      After Raduechel resigned, Matkin inquired into Spain’s interest in becoming
the branch manager at PFS Oskaloosa. On June 14, 2004, Spain was offered the
branch manager job for a base salary of $110,000. Spain rejected the offer on June
15, 2004, and resigned that same day. Raduechel and Spain started operating D&B
Solutions after Spain resigned, and Affiliated and Fareway began buying poultry from
D&B Solutions around late June to early July 2004.

       On June 21, 2004, PFS filed a complaint in the district court against Raduechel,
Spain, and D&B Solutions seeking damages and injunctive relief for breach of
fiduciary duties, civil conspiracy, and unjust enrichment and constructive trust. PFS
subsequently added copyright infringement and misappropriation of trade secret
claims, and the district court granted a preliminary injunction against the operation of
D&B Solutions on August 11, 2004. After the preliminary injunction was entered,
D&B Solutions stopped operation; however, Fareway and Affiliated did not return to
PFS Oskaloosa as customers, and instead began buying poultry directly from the
companies’ preferred poultry suppliers.

      On August 30, 2004, PFS sent a letter to Raduechel explaining PFS would not
pay Raduechel the bonus which was due under Raduechel’s ConAgra Poultry
compensation agreement and incentive plan that expired on May 30, 2004. PFS stated
Raduechel was not entitled to the bonus under the terms of the incentive plan due to
PFS’s complaint against Raduechel and the district court’s grant of a preliminary
injunction. As a result, Raduechel filed a counterclaim against PFS for payment of



                                          -5-
the bonus alleging (1) violation of the Iowa Wage Payment Collection Act (IWPCA),
(2) breach of oral contract, (3) breach of written contract, and (4) promissory estoppel.

      PFS amended its complaint, adding Donohue, TD&T, MidWestOne, Hicks, and
Pothoven as defendants on the civil conspiracy, constructive trust and unjust
enrichment, and misappropriation of trade secrets claims. PFS also added a claim for
aiding and abetting against all defendants.

      On February 7, 2005, PFS moved to dismiss Raduechel’s counterclaim under
Fed. R. Civ. P. 12(b)(6). The district court granted the motion on August 9, 2005.
Raduechel then moved the district court to reconsider its ruling on PFS’s motion to
dismiss. The district court denied Raduechel’s motion for reconsideration on January
17, 2006.

       On January 8, 2007, the district court addressed summary judgment motions
from Pothoven, MidWestOne, Hicks, PFS, Donohue, and TD&T. The district court
(1) granted Pothoven’s motion for summary judgment and dismissed Pothoven from
the action; (2) granted Donohue’s and TD&T’s motion on the constructive trust and
unjust enrichment claim, and (3) granted partial summary judgment to PFS on the
issue of Raduechel’s and Spain’s liability for breach of fiduciary duties and
misappropriation of trade secrets. The district court left for trial the issues of
causation and damages on the breach of fiduciary duties and misappropriation of trade
secrets claims against Raduechel and Spain, and denied the summary judgment
motions in all other respects. Raduechel and Spain subsequently moved the district
court to reconsider the grant of summary judgment, but the district court denied the
motion.

      Before trial, the parties agreed PFS’s claim for unjust enrichment and
constructive trust should be stayed until the resolution of the legal claims in PFS’s



                                          -6-
amended complaint. Thus, the district court ordered all evidence regarding PFS’s
claim for unjust enrichment and constructive trust be withheld until after trial.

       A jury trial began on February 12, 2007. On February 27, 2007, the jury
returned a verdict in favor of all defendants on all of the remaining claims. The jury
found (1) Raduechel’s and Spain’s breach of fiduciary duties and misappropriation of
trade secrets were not proximate causes of damage to PFS; (2) the Accounting and
Banking Defendants had not misappropriated trade secrets; (3) the Accounting and
Banking Defendants did not enter into a conspiracy with Raduechel and Spain; and
(4) the Accounting and Banking Defendants did not aid and abet Raduechel’s and
Spain’s breach of fiduciary duties. The jury did not address the issue of damages.

       After trial, PFS moved for equitable relief in conjunction with the unjust
enrichment and constructive trust claim which had been stayed. PFS asked the district
court for disgorgement of Raduechel’s and Spain’s salaries during the time Raduechel
and Spain were breaching their fiduciary duties. On September 12, 2007, the district
court found it would not be equitable to require Raduechel and Spain to disgorge their
salaries, and denied PFS’s motion.

       PFS then moved the district court for a new trial, arguing the jury’s finding of
no proximate cause on the breach of fiduciary duties and misappropriation of trade
secrets claims against Raduechel and Spain, as well as the jury’s findings on the
conspiracy and aiding and abetting claims, were against the greater weight of the
evidence. The district court denied PFS’s motion. This appeal follows.

II.  DISCUSSION
     A.    Motion for a New Trial on the Breach of Fiduciary Duties and
           Misappropriation of Trade Secrets Claims
     PFS first challenges the district court’s denial of PFS’s motion for a new trial
on PFS’s breach of fiduciary duties and misappropriation of trade secrets claims


                                         -7-
against Raduechel and Spain. The district court found PFS was not entitled to a new
trial because there was evidence PFS’s initial losses after Raduechel and Spain left
were offset by PFS’s retention of Raduechel’s and Spain’s bonuses, and there was
evidence any prolonged loss suffered by PFS was caused by the large sum PFS paid
in attorney fees for the litigation and PFS’s failure to act quickly to regain Affiliated
and Fareway as customers. The district court noted PFS’s effort to regain Affiliated
and Fareway as customers and PFS’s attorney fees were “technically . . . relevant to
the issue of damages.” However, the district court concluded, “In the context of the
present action, the Court finds that any distinction between proximate cause and
damages is largely academic,” and “[u]nder this scenario, the issue of proximate cause
was subsumed by the issue of damages, and the jury appropriately answered ‘no’ on
the question that appeared first in the verdict forms.”

       PFS, primarily relying on Storage Tech. Corp. v. Cisco Sys., Inc., 

(8th Cir. 2005), and Vigoro Indus., Inc. v. Crisp, 

 (8th Cir. 1996), now
maintains it was entitled to a new trial because no reasonable jury could have found
Raduechel’s and Spain’s misconduct did not proximately cause damage to PFS when
the evidence at trial showed Fareway and Affiliated stopped buying chicken from
PFS, and began buying chicken from D&B Solutions, in the summer of 2004.2 PFS
further contends the district court’s reasoning was erroneous because the district court
improperly conflated the issues of proximate cause and damages by equating the
jury’s no proximate cause finding with a finding of no damages. PFS also refutes the

      2
        In support of this argument, PFS’s counsel submitted a Fed. R. App. P. 28(j)
letter urging us also to consider Navigant Consulting, Inc. v. Wilkinson, 

(5th Cir. 2007). Fed. R. App. P. 28(j) allows a party to submit “pertinent and
significant authorities [which] come to a party’s attention after the party’s brief has
been filed—or after oral argument but before decision.” Navigant was decided 17
months before oral argument in this case. We prefer that authorities cited in a 28(j)
letter “consist of ‘intervening decisions or new developments.’” Davis v. U.S.
Bancorp, 

, 763-64 n.2 (8th Cir. 2004) (quoting 8th Cir. R. Appx. III(I)(2)
(2004)). Nonetheless, we find Navigant is not controlling or persuasive in this case.

                                          -8-
district court’s reasoning by asserting (1) PFS was damaged by the loss of Affiliated
and Fareway as customers regardless of PFS’s net losses or PFS’s retention of
Raduechel’s and Spain’s bonuses; (2) PFS’s effort to regain Affiliated and Fareway
as customers is irrelevant to proximate causation; and (3) in the event we find a new
trial is warranted, the hypothetical possibility that Raduechel and Spain could have
quit PFS and lawfully formed D&B Solutions is not a defense to proximate causation
or damages.

       We review a district court’s denial of a motion for a new trial for abuse of
discretion. See Keeper v. King, 

, 1314 (8th Cir. 1997). When a motion
for a new trial is founded on the assertion that “the jury’s verdict is against the weight
of the evidence,” the district court’s ruling is “virtually unassailable on appeal.” Id.
(internal quotations and citations omitted). “Viewing the evidence in the light most
favorable to the verdict,” Computrol, Inc. v. Newtrend, L.P., 

, 1068–69
(8th Cir. 2000), “we will reverse only when there is an absolute absence of evidence
to support the jury’s verdict.” Slidell, Inc. v. Millennium Inorganic Chems., Inc., 

, 1057 (8th Cir. 2006) (citation omitted). The crucial determination “is
whether a new trial should have been granted to avoid a miscarriage of justice.”
Keeper, 130 F.3d at 1314 (internal marks and citation omitted).

      The Iowa Supreme Court has endorsed the definition of “proximate cause”
which the district court used in the jury instructions in this case, and which provides,

            The conduct of a party is a proximate cause of damage when it is
      a substantial factor in producing damage and when the damage would
      not have happened except for the conduct. “Substantial” means the
      party’s conduct has such an effect in producing damage as to lead a
      reasonable person to regard it as a cause.

           There can be more than one proximate cause of an injury or
      damage.


                                           -9-
See Benn v. Thomas, 

, 539-40 (Iowa 1994). The Iowa Supreme
Court has also explained,

      Courts have recognized a distinction between proof of the fact that
      damages have been sustained and proof of the amount of those damages.
      If it is speculative and uncertain whether damages have been sustained,
      recovery is denied. If the uncertainty lies only in the amount of
      damages, recovery may be had if there is proof of a reasonable basis
      from which the amount can be inferred or approximated.

Orkin Exterminating Co. v. Burnett, 

, 430 (Iowa 1968) (citations
omitted).

       Under Iowa law, a reasonable jury could have concluded Raduechel’s and
Spain’s misconduct did not proximately cause PFS to lose Affiliated and Fareway as
customers. First, the jury was presented evidence that Fareway was planning to leave
PFS regardless of Raduechel’s and Spain’s formation of D&B Solutions. Fareway’s
head meat buyer, Rod Nedved (Nedved), testified Fareway had encountered problems
with PFS and had discussed leaving PFS several months before D&B Solutions was
formed. Fareway’s vice president of purchasing, Randy Naeve (Naeve), corroborated
Nedved’s testimony. Spain also testified Fareway had left PFS and bought some
poultry products directly from a supplier from 2001 to 2003, and Nedved testified it
was inevitable Fareway would leave PFS and begin buying direct from a supplier.
Nedved further testified the operation of D&B Solutions was not the sole reason
Fareway left PFS, but rather, leaving PFS to buy direct was more financially sound,
easier for communication, and more reliable. Although PFS contends this testimony
does not account for the time when Fareway left PFS and was buying chicken through
D&B Solutions in the summer of 2004, we conclude Spain’s, Nedved’s, and Naeve’s
testimonies provide a reasonable basis for a jury to conclude (1) Fareway was
planning to leave PFS and buy direct regardless of the operation of D&B Solutions;
and (2) Fareway stopped doing business with PFS and began doing business with


                                       -10-
D&B Solutions in the summer of 2004, not because of Raduechel’s and Spain’s
misconduct in forming D&B Solutions, but because Fareway had encountered
problems with PFS before the formation of D&B Solutions.

       Second, a reasonable jury could conclude PFS lost Affiliated and Fareway as
customers due to PFS’s own actions. Raduechel testified he initially expected a
proposed compensation package from PFS in late January 2004, approximately four
months before the expiration of Raduechel’s ConAgra compensation agreement, but
did not receive a proposed compensation package from PFS until May 26, 2004, four
days before Raduechel’s ConAgra compensation agreement expired. Matkin, PFS’s
vice president of logistics and distribution, admitted PFS was taking a significant risk
that Raduechel would leave and compete with PFS when PFS delayed offering
Raduechel a compensation package until a few days before Raduechel’s ConAgra
Poultry agreement expired. Further, Raduechel testified (1) PFS’s first compensation
proposal involved approximately half of the compensation Raduechel previously had
with ConAgra Poultry, and increased work and responsibility with PFS’s Green Bay
office; (2) PFS’s modified compensation proposal, after Raduechel rejected the first
proposal, eliminated the increased work and responsibility with PFS’s Green Bay
office, but still required Raduechel to take an approximate 50% pay cut; (3) Raduechel
felt PFS “could not find a way to compensate me and was expecting me to leave”;
and (4) D&B Solutions was “Plan B” for Raduechel up until Raduechel submitted his
resignation.

        The director of meat operations for Affiliated, Mike Wallace (Wallace),
testified Affiliated bought poultry from Raduechel because Wallace trusted Raduechel
and valued Raduechel’s service. Wallace further testified he would have bought from
Raduechel regardless of whether Raduechel was employed by PFS or D&B Solutions.
Viewing the evidence in the light most favorable to the jury verdict, Raduechel’s,
Matkin’s, and Wallace’s testimonies provide a reasonable basis for a jury to conclude
Wallace would have followed Raduechel regardless of Raduechel’s employer, and

                                         -11-
thus PFS, not Raduechel’s and Spain’s misconduct, caused the loss of Affiliated as a
customer, because PFS did not adequately take actions to retain Raduechel and
thereby preserve PFS’s relationship with Affiliated.

        Similarly, Naeve testified that, prior to the formation of D&B Solutions,
Fareway had encountered quality and accuracy problems with PFS’s deliveries,
namely Fareway had received some ice-packed poultry and had received some poultry
from suppliers other than Fareway’s preferred supplier. Naeve’s testimony was
corroborated by Nedved, who also testified about the quality and accuracy issues
Fareway had with PFS’s deliveries before D&B Solutions began operating. Nedved
testified Fareway began buying poultry from Spain at D&B Solutions due to Spain’s
ability to guarantee poultry from Fareway’s preferred supplier, and stated Fareway
could buy poultry from any supplier “if [Fareway] maybe had issues or reasons to go
another direction.” A reasonable jury could conclude, based on this testimony, PFS
lost Fareway as a customer in the summer of 2004 due to PFS’s quality and accuracy
problems, not necessarily the formation and operation of D&B Solutions.

       Finally, PFS’s reliance on Storage Tech and Vigoro is not persuasive. In
Vigoro, we affirmed a district court’s finding that an employee breached fiduciary
duties. See Vigoro, 82 F.3d at 789. However, our discussion did not analyze whether
the district court properly found the breaches proximately caused damage. Rather, our
discussion focused on (1) whether the district court properly found the employee had
breached fiduciary duties, and (2) whether the district court erred in determining the
amount of damages. See id. at 788-90. Vigoro, thus, does not apply to the specific
proximate cause arguments PFS makes in this case. Similarly, in Storage Tech, we
held, under Minnesota law, an employer had not proven the certainty of damages for
claims of breach of fiduciary duties and misappropriation of trade secrets because the
employer failed to produce enough evidence for a jury to calculate damages. See id.
at 928-29. This discussion regarding the certainty of damages under Minnesota law



                                        -12-
is different from our examination of PFS’s specific proximate cause arguments, and
does not influence our analysis in this case.

       We conclude the jury’s proximate cause finding was not a miscarriage of
justice, and the district court did not abuse its considerable discretion in denying
PFS’s motion for a new trial on the breach of fiduciary duties and misappropriation
of trade secrets claims. Because we conclude a reasonable jury could have found
Raduechel’s and Spain’s formation and operation of D&B Solutions did not
proximately cause PFS to lose Affiliated and Fareway as customers, we choose not
to address PFS’s other contentions regarding the district court’s reasoning for
upholding the jury verdict. See Palavra v. I.N.S., 

, 693 (8th Cir. 2002)
(“In reviewing district courts, we may affirm the judgment on any basis disclosed in
the record, whether or not the district court agreed with or even addressed that
ground.”).

      B.    Conspiracy Claim
      PFS next argues the district court erred in its treatment of PFS’s conspiracy
claim against the Accounting and Banking Defendants because the district court
(1) should have granted PFS’s motion for a new trial on the conspiracy claim, and
(2) improperly instructed the jury on the conspiracy claim.

              1.    New Trial Motion
       PFS contends it was entitled to a new trial on the conspiracy claim against the
Accounting and Banking Defendants because the evidence at trial showed the
Accounting and Banking Defendants (1) knew Raduechel and Spain were top
executives at PFS, (2) knew D&B Solutions would directly compete with PFS, and
(3) knew D&B Solutions planned to take a significant portion of PFS’s business. PFS
asserts this evidence demonstrates the Accounting and Banking Defendants knew
Raduechel and Spain were acting improperly, and thus the Accounting and Banking
Defendants had the requisite knowledge and intent to enter into a conspiracy. PFS

                                        -13-
also claims the district court erred in justifying the jury verdict with an “advice of
counsel” defense and a “mistake of law” defense.

       We review the district court’s denial of PFS’s motion for a new trial for abuse
of discretion, and give the district court’s ruling high deference. See Keeper, 130 F.3d
at 1314. Under Iowa law, “[l]iability for civil conspiracy requires an agreement
between the actor and the party sought to be held liable.” Wright v. Brooke Group
Ltd., 

, 174 (Iowa 2002) (citation omitted). This agreement “must
exist between the two persons to commit a wrong against another,” Ezzone v.
Riccardi, 

, 398 (Iowa 1994), and “results only from a defendant’s
knowing and voluntary participation in a common scheme to take action, lawful or
unlawful, that ultimately subjects the actor to liability to another.” Wright, 652
N.W.2d at 174 (internal marks and citations omitted).

                    a.    Accounting Defendants
      The district court found PFS was not entitled to a new trial on the conspiracy
claim against the Accounting Defendants because Donohue testified he did not know
Raduechel and Spain were breaching fiduciary duties and he did not intend to help
Raduechel and Spain damage PFS. The district court also reasoned the Accounting
Defendants’ expert, Susan Chantland (Chantland), testified Donohue’s actions were
consistent with prevailing accounting practices. The district court found Donohue’s
and Chantland’s testimonies credible and consistent with a jury finding that the
Accounting Defendants lacked the required intent to engage in a conspiracy, and thus
a new trial was not warranted. We agree with the district court.

      Donohue testified he never heard Raduechel or Spain state it was Raduechel’s
or Spain’s intent to conspire to injure PFS, and it was not Donohue’s impression that
it was Raduechel’s or Spain’s intent to injure PFS. Rather, Donohue stated he
believed Raduechel and Spain were staying at PFS after consulting Donohue, and
Donohue would not have worked with Raduechel and Spain if he knew Raduechel and

                                         -14-
Spain were acting to injure PFS. Donohue further testified (1) Donohue did not create
a business plan, or financial projections, for Raduechel and Spain; (2) Donohue only
analyzed the general flow of the calculations Raduechel and Spain provided Donohue;
(3) Donohue did not encourage, or actively participate, in the formation of D&B
Solutions; (4) Donohue was not aware of the use of confidential information from the
documents Raduechel provided Donohue; (5) Donohue advised Raduechel to get legal
advice when he recognized possible confidential information on the documents; and
(6) although Donohue inadvertently retained the documents Raduechel provided him,
Donohue never used, reviewed, or published the documents after identifying the
possible legal concern with the documents.

      Chantland testified, under professional accounting standards, Donohue’s ability
and responsibility to determine whether Raduechel and Spain were breaching their
fiduciary duties was beyond Donohue’s province as an accountant. Chantland also
opined Donohue acted within all professional accounting standards during his service
to Raduechel and Spain.

       Based upon Donohue’s and Chantland’s testimonies, the record contains
sufficient evidence to substantiate the jury verdict because Donohue’s and
Chantland’s testimonies reasonably show the Accounting Defendants did not
knowingly and voluntarily enter into a scheme with Raduechel and Spain to breach
Raduechel’s and Spain’s fiduciary duties or misappropriate trade secrets. The district
court did not abuse its discretion by denying PFS’s motion for a new trial on the
conspiracy claim against the Accounting Defendants, nor does a miscarriage of justice
exist.

                   b.     Banking Defendants
      Similar to its finding for the Accounting Defendants, the district court also
found PFS was not entitled to a new trial on the conspiracy claim against the Banking
Defendants. The district court reasoned Hicks’s testimony established the Banking

                                        -15-
Defendants were not aware of an unlawful scheme by Raduechel and Spain to breach
fiduciary duties or misappropriate trade secrets. The district court concluded Hicks’s
testimony provided a basis for the jury verdict because the evidence reasonably
showed the Banking Defendants did not possess the requisite knowledge to enter into
a conspiracy. We agree with the district court.

       Like Donohue, Hicks testified he never heard Raduechel or Spain state it was
Raduechel’s and Spain’s intent to injure PFS, and Hicks never had the impression it
was Raduechel’s and Spain’s intent to conspire against, or injure, PFS. Hicks
explicitly stated he never had an agreement with Raduechel, Spain, and Donohue to
injure PFS. Hicks also testified he believed Raduechel and Spain were employees at-
will, he did not know about a contract for Spain, and he believed Raduechel’s contract
with PFS had expired. Hicks further testified he had no knowledge of, and never saw
or reviewed, the documents which PFS alleged contained trade secrets.

        The Banking Defendants’ expert, Michael Guttau (Guttau), testified it was
relatively frequent for a bank to consider a loan application and grant a loan to an
employee who wants to start a competing business with an employer, even before the
employee has resigned from the employer. Guttau also testified it would not be a “red
flag” for a bank to have two top executives come to a bank and apply for a loan to
start a business which would compete with the executives’ employer. Guttau further
attested to the banking procedures used by the Banking Defendants, and after
reviewing the Banking Defendants’ file for D&B Solutions, Guttau opined the
information on Raduechel’s and Spain’s loan application would not trigger concern
over the confidentiality of the information.

       A reasonable jury could find Hicks’s and Guttau’s testimonies credible, and
based upon their testimonies, find the Banking Defendants did not have knowledge
of a scheme by Raduechel and Spain to breach fiduciary duties or misappropriate trade
secrets. Thus, Hicks’s and Guttau’s testimonies provide a basis for the jury’s verdict,

                                         -16-
and the district court’s denial of PFS’s motion for a new trial on the conspiracy claim
against the Banking Defendants did not create a miscarriage of justice.

       Finally, we are not persuaded by PFS’s contention that the district court’s order
erroneously relied on “advice of counsel” and “mistake of law” defenses. We do not
read the district court’s order as basing the ruling on these defenses, and we choose
not to address further PFS’s allegations. We conclude the district court did not
erroneously deny PFS’s motion for a new trial on the conspiracy claim.

              2.    Jury Instruction
       PFS also contends the district court’s jury instruction on the conspiracy claim
was erroneous. PFS asserts its theory on the conspiracy claim was that Raduechel and
Spain “were using unlawful means (soliciting one another) to accomplish” the lawful
end of “forming D&B Solutions.” PFS claims the district court failed to instruct the
jury on PFS’s theory because the district court declined to use PFS’s proposed jury
instruction, which would have instructed the jury that “[a] conspiracy is a combination
of two or more persons to accomplish, through concerted actions, an unlawful end or
a lawful end by an unlawful means.”

      The district court’s instruction defined conspiracy as follows:

             A conspiracy is an agreement of two or more persons to commit
      a wrong against another. The agreement can be oral or written, informal
      or formal, and need not be detailed. The agreement need not be
      expressed in words and may be implied and understood to exist from the
      conduct itself. It may be proved by direct or circumstantial evidence.
      Merely because two or more persons associate with each other, or meet
      to discuss common interests or goals does not, by itself, establish a
      conspiracy.

            A person participates in a conspiracy when the person joins the
      agreement with the intention to accomplish the wrongful act. A

                                         -17-
       participant need not know all the details of the agreement nor all of the
       other participants. One who innocently furthers wrongful conduct by
       another does not participate in a conspiracy.

        “We review a district court’s jury instructions for abuse of discretion.” Mems
v. City of St. Paul Dep’t of Fire and Safety Servs., 

, 781 (8th Cir. 2003)
(citation omitted). “[W]e ask ‘whether the instructions, taken as a whole and viewed
in the light of the evidence and applicable law, fairly and adequately submitted the
issues in the case to the jury.’” Id. (quoting Wheeling Pittsburgh Steel Corp. v.
Beelman River Terminals, Inc., 

, 711 (8th Cir. 2001)). “‘[A] district
court has broad discretion in instructing the jury, and jury instructions do not need to
be technically perfect or even a model of clarity.’” Id. (quoting B&B Hardware, Inc.
v. Hargis Indus., Inc., 

, 1012 (8th Cir. 2001)). “We will reverse only
upon a finding that the instructional error affected the substantial rights of the parties.”
Id. (citing Wheeling, 254 F.3d at 711).

       The district court’s conspiracy instruction was not an abuse of discretion. The
instruction followed the Iowa Model Civil Jury Instruction defining both civil
conspiracy and participation in a civil conspiracy. See Iowa Model Civil Jury
Instructions 3500.2, 3500.3. This instruction is consistent with Iowa law. See id.
(citing Iowa authority); see also Robbins v. Heritage Acres, 

, 265
(Iowa Ct. App. 1998) (“A civil conspiracy requires proof of an agreement or
understanding to effect a wrong against another.” (citation omitted)); Ezzone, 525
N.W.2d at 398 (“For conspiracy, an agreement must exist between the two persons to
commit a wrong against another.”).

       Because the instructions stated, “[a] conspiracy is an agreement of two or more
persons to commit a wrong against another,” the instructions allowed the jury to find
for or against PFS on its theory that the Banking and Accounting Defendants were
agreeing to perpetrate the wrong of breach of fiduciary duty or misappropriation of
trade secrets. The instruction was broad enough to encompass situations involving

                                           -18-
“an unlawful end or a lawful end by unlawful means.” Robbins, 578 N.W.2d at 265.
Although PFS would have preferred more specific language, the district court’s
instruction fairly and adequately presented the Iowa conspiracy claim to the jury, and
was not erroneous. See Campbell v. Vinjamuri, 

, 1277 (8th Cir. 1994)
(“The trial court has a great deal of discretion in framing the jury instructions and the
court need not give the exact language desired by the parties.” (citing McIlroy v.
Dittmer, 

, 102-03 (8th Cir. 1984))). The instruction provided PFS with
sufficient guidance to argue PFS’s case and themes.

      C.    Aiding and Abetting Claim
      Similar to the conspiracy claim, PFS charges the district court erroneously
denied PFS’s motion for a new trial on the aiding and abetting claim against the
Accounting and Banking Defendants. PFS also argues the district court gave an
erroneous instruction on the aiding and abetting claim.

             1.     New Trial Motion
      The district court found, based on the testimonies of Donohue and Hicks, the
greater weight of the evidence established the Accounting and Banking Defendants
did not have the requisite knowledge for aiding and abetting. The district court thus
concluded PFS was not entitled to a new trial on this claim.

        PFS now asserts the district court’s ruling was improper. PFS claims it was
entitled to a new trial because the Accounting and Banking Defendants were highly
sophisticated business people whom no reasonable jury could find did not understand
Raduechel and Spain were engaged in wrongful conduct. PFS thus maintains, because
the Accounting Defendants provided assistance on the business plan for D&B
Solutions and the Banking Defendants extended credit to D&B Solutions, no
reasonable jury could conclude the Accounting and Banking Defendants were not
liable for aiding and abetting, and the evidence “established aiding and abetting
liability as a matter of law.”

                                          -19-
       We review PFS’s contention for abuse of discretion. See Keeper, 130 F.3d at
1314. Under Iowa law, a claim for aiding and abetting another’s wrongful act can be
maintained if a person “‘knows that the other’s conduct constitutes a breach of duty
and gives substantial assistance or encouragement to the other so to conduct himself.’”
Reilly v. Anderson, 

, 107 (Iowa 2006) (quoting Restatement (Second)
of Torts § 876(b) at 315 (1979)).

        As noted in our discussion of the conspiracy claim, Donohue testified he was
not aware of Raduechel’s and Spain’s breach of fiduciary duties or misappropriation
of trade secrets, and stated he would not have worked with Raduechel and Spain if he
had known of any misconduct. Chantland corroborated Donohue’s testimony by
stating Donohue’s ability and responsibility as an accountant to comprehend breach
of fiduciary duties or misappropriation of trade secrets is limited. Similarly, Hicks
testified to an unawareness of any breach of fiduciary duties or misappropriation of
trade secrets by Raduechel and Spain. Guttau opined the Banking Defendants’ file for
D&B Solutions was handled properly and generally would not raise concerns for
breach of fiduciary duties or misappropriation of trade secrets. This evidence provides
a reasonable basis for a jury to conclude the Accounting and Banking Defendants did
not know Raduechel’s and Spain’s conduct was improper, and the district court was
within its discretion to deny PFS’s motion on the aiding and abetting claim.

             2.     Jury Instruction
       PFS also challenges the district court’s jury instruction on the aiding and
abetting claim. We give high deference to the district court’s jury instructions, and
only reverse if there has been an abuse of discretion. See Mems, 327 F.3d at 781.

       As one element of the aiding and abetting claim, the district court instructed the
jury PFS was required to prove “[t]he defendant whose case you are considering knew
that the conduct of Raduechel and/or Spain constituted a breach of fiduciary duty to
[PFS] and/or a misappropriation of [PFS]’s trade secrets.” PFS argues this portion of

                                          -20-
the district court’s instruction required PFS to prove the Accounting and Banking
Defendants understood, as a matter of law, that Raduechel and Spain were breaching
fiduciary duties. PFS contends, relying on FDIC v. First Interstate Bank of Des
Moines, 

 (8th Cir. 1989) and Tubbs v. United Central Bank, 

 (Iowa 1990), that Iowa law and public policy do not require proof of actual
knowledge of the wrongdoing, but only require proof of a “general awareness” of the
wrongdoing. PFS thus asserts the district court’s instruction placed an erroneously
high burden on PFS to prove the aiding and abetting claim.

       PFS’s argument is unpersuasive. Similar to the district court’s conspiracy
instruction, the district court’s aiding and abetting instruction closely tracked the Iowa
Model Civil Jury Instruction for aiding and abetting. See Iowa Model Civil Jury
Instruction 3500.4. This instruction is grounded in Iowa law. See id. (citing Iowa
authority); see also Ezzone, 525 N.W.2d at 398 (“As to aiding and abetting, there must
be a wrong to the primary party, knowledge of the wrong on the part of the aider, and
substantial assistance by the aider in the achievement of the primary violation.” (citing
Tubbs, 451 N.W.2d at 182)).

       Further, PFS’s reliance on First Interstate and Tubbs is misplaced. In First
Interstate, 885 F.2d at 429-30, this court discussed the “general awareness” standard
in jury instructions for a claim involving federal law developed under Section 10(b)
of the Securities and Exchange Act of 1934, not Iowa law. First Interstate, 885 F.2d
at 429-30. Similarly, in Tubbs, 451 N.W.2d at 183 (citing First Interstate, 885 F.2d
at 430-31), the Supreme Court of Iowa acknowledged “general awareness” has been
the recognized standard in federal securities cases. The Tubbs court then analyzed the
merits of an Iowa common law aiding and abetting claim assuming “‘general
awareness’ by an alleged aider and abettor [was] sufficient to constitute knowledge.”
Tubbs, 451 N.W.2d at 183. The Tubbs court did not address or adopt the “general
awareness” standard under Iowa common law because, even under the “more liberal
definition” of “general awareness,” knowledge was not established in that case. Id.

                                          -21-
Neither First Interstate nor Tubbs clearly establishes a “general awareness” standard
for Iowa common law aiding and abetting, and the district court did not abuse its
discretion in following Iowa Model Civil Jury Instruction 3500.4 and excluding any
proposed “general awareness” language from the aiding and abetting jury instruction.

       D.    Admission of Expert Testimonies
       PFS next contends the district court erred in allowing the expert testimonies of
Chantland and Guttau. PFS claims Chantland’s and Guttau’s expert testimonies were
irrelevant because the case was an intentional tort case rather than a negligence or
professional malpractice case. PFS also argues the testimonies of Chantland and
Guttau were prejudicial because the district court gave an erroneous jury instruction
on knowledge for the aiding and abetting claim.

       “We will reverse the district court’s decision to admit expert testimony only if
it amounts to a prejudicial abuse of discretion.” Rottlund Co. v. Pinnacle Corp., 

, 731 (8th Cir. 2006) (citing Moses.com Sec., Inc. v. Comprehensive
Software Sys., Inc., 

, 1058-59 (8th Cir. 2005)). Under Fed. R. Evid.
702, an expert witness with specialized knowledge may testify if the testimony will
assist the trier of fact. Rule 702 is a rule “‘of admissibility rather than exclusion.’”
Jenson v. Eveleth Taconite Co., 

, 1298 (8th Cir. 1997) (quoting Arcoren
v. United States, 

, 1239 (8th Cir. 1991)).

       Under the conspiracy and aiding and abetting claims, the knowledge, or state
of mind, of the Accounting and Banking Defendants was an issue the jury was
required to determine. See Wright, 652 N.W.2d at 174 (stating, a conspiracy must
contain an agreement which “results only from a defendant’s knowing and voluntary
participation in a common scheme to take action” (emphasis added)); Reilly, 727
N.W.2d at 107 (explaining, an aiding and abetting claim involves a defendant who
“‘knows that the other’s conduct constitutes a breach of duty’” (quoting Restatement
(Second) of Torts § 876(b) (emphasis added)).

                                         -22-
       Chantland’s and Guttau’s testimonies were relevant to the knowledge and state
of mind of the Accounting and Banking Defendants for the conspiracy and aiding and
abetting claims. Chantland testified about Donohue’s professional responsibilities and
capacities, and concluded Donohue acted in compliance with professional accounting
standards. Likewise, Guttau testified the Banking Defendants correctly handled the
file for D&B Solutions under prevailing Iowa banking standards, and the file
contained no “red flags” which would notify the Banking Defendants that Raduechel
and Spain were engaged in misconduct. Chantland’s and Guttau’s testimonies placed
the actions and testimonies of the Accounting and Banking Defendants in the
professional contexts involved in this case, and provided a basis from which the jury
could evaluate the knowledge and state of mind of the Accounting and Banking
Defendants during their service to Raduechel and Spain. Although conspiracy and
aiding and abetting are intentional torts, the knowledge and state of mind of the
Accounting and Banking Defendants were issues in these claims, and the district court
did not abuse its discretion in finding Chantland’s and Guttau’s testimonies were
relevant and would assist the jury.

      Because we find there was no error in the district court’s aiding and abetting
jury instruction, PFS’s claim that Chantland’s and Guttau’s testimonies were
prejudicial is without merit. The district court did not err in admitting the testimonies
of Chantland and Guttau.

      E.     Denial of Equitable Relief
      PFS’s final argument is the district court abused its discretion in denying PFS
equitable relief in the form of disgorgement of Raduechel’s and Spain’s salaries
during the time Raduechel and Spain were breaching their fiduciary duties. PFS
contends public policy surrounding both deterrence and duties of fiduciaries mandates
Raduechel and Spain forfeit their salaries. PFS also asserts salary forfeiture is
warranted as a matter of restitution separate from the jury’s verdict.



                                          -23-
       “We review a district court’s denial of equitable relief for an abuse of
discretion.” Rodgers v. City of Des Moines, 

, 909 (8th Cir. 2006) (citing
Midwest Oilseeds, Inc. v. Limagrain Genetics Corp., 

, 715 (8th Cir.
2004)). Under Iowa law, “[t]he doctrine of unjust enrichment is based on the principle
that a party should not be permitted to be unjustly enriched at the expense of another
or receive property or benefits without paying just compensation.” Iowa Dep’t of
Human Services ex rel. Palmer v. Unisys Corp., 

, 154 (Iowa 2001)
(citation omitted). One of three elements a district court is required to analyze for an
unjust enrichment claim is whether “it is unjust to allow the defendant to retain the
benefit under the circumstances.” Id. at 154-55 (emphasis added).

      The district court found it would not be equitable to require Raduechel and
Spain to disgorge their salaries because (1) Raduechel and Spain received no profits
from D&B Solutions, (2) Raduechel and Spain did not receive their bonuses from
PFS, (3) Raduechel and Spain suffered severe financial hardship as a result of D&B
Solutions’s dissolution, (4) Raduechel and Spain only acquired lower paying
employment, and (5) the preliminary injunction was a sufficient sanction for
Raduechel’s and Spain’s misconduct.

       PFS conceded in its brief the district court’s factual findings were correct.
Based upon these findings, the district court was within its broad discretion to
conclude the equities of this case did not require Raduechel and Spain to disgorge
their 2004 salaries. The district court therefore did not commit error in denying PFS’s
unjust enrichment claim.

      F.     Raduechel’s and Spain’s Cross Appeal
             1.     Motion to Dismiss
      On cross appeal, Raduechel argues the district court improperly dismissed his
counterclaim for payment of a bonus. Raduechel contends his IWPCA claim and
breach of written contract claim could not be dismissed on a Fed. R. Civ. P. 12(b)(6)

                                         -24-
motion because Raduechel’s employment contract contains ambiguities. Raduechel
also asserts summary disposition of his breach of oral contract and promissory
estoppel claims was improper because PFS officials made promises that Raduechel
would receive his bonus, which promises were independent of, and subsequent to, his
written employment contract.

      “This court reviews de novo the grant of a motion to dismiss, taking all facts
alleged in the complaint as true.” Charles Brooks Co. v. Georgia-Pacific, LLC, 

, 721 (8th Cir. 2009) (internal marks and citations omitted). “Dismissal is
proper where the plaintiffs’ complaint fails to state a claim upon which relief can be
granted.” Id. (citation omitted). “[T]he complaint must contain sufficient facts, as
opposed to mere conclusions, to satisfy the legal requirements of the claim to avoid
dismissal.” Levy v. Ohl, 

, 991 (8th Cir. 2007) (internal marks and
quotation omitted).

       Raduechel failed to raise the specific arguments he makes on appeal to the
district court when opposing PFS’s motion to dismiss Raduechel’s counterclaim. We
cannot say Raduechel waived these arguments, however, because the district court did
address the arguments in its order on Raduechel’s motion to reconsider the dismissal
of Raduechel’s counterclaim. See Anderson v. Unisys Corp., 

, 765 (8th
Cir. 1995) (deciding not to address issues which had not been passed on by the district
court).

       The district court found Raduechel’s employment contract did not contain
ambiguities, and did not conflict with or diminish PFS’s discretion in paragraph 1 of
the General Provisions of Raduechel’s employment contract which allowed PFS to
withhold all of Raduechel’s bonus if Raduechel’s “performance [was] unsatisfactory”
or his “managerial attitude was not in the best interest of [PFS].” Thus, the district
court concluded the alleged ambiguities did not require the district court to reverse its



                                          -25-
initial decision to dismiss the claims involving Raduechel’s written employment
contract.

       The district court also found the alleged oral contracts were not independent
contracts, but rather assurances which “re-state the language memorialized in
paragraph 15 of [Raduechel’s employment contract], protecting bonuses to which a
participant otherwise would be entitled in the event of a change in control.” Finally,
the district court, citing Iowa law, held dismissal of Raduechel’s promissory estoppel
claim was appropriate because the use of promissory estoppel is limited to situations
not involving a written contract. Because Raduechel had an employment contract and
did not allege PFS made promises for compensation outside the employment contract,
Raduechel could not recover under a theory of promissory estoppel. We agree with
the district court’s well-reasoned analysis of this issue.

       The provisions Raduechel cites in his written agreement do not create
ambiguities, or limit PFS’s ability to withhold Raduechel’s bonus if PFS finds, in its
discretion, Raduechel’s actions were unsatisfactory or against the interest of PFS. See
Vigoro, 82 F.3d at 791 (holding, absent an allegation of “fraud, bad faith, or a grossly
mistaken exercise in judgment,” an employee was not entitled to payment of a bonus
when a contract term gave the employer discretion to withhold payment of the bonus
based upon the employee’s disloyal conduct (quoting Golden v. Kentile Floors, Inc.,

, 847 (5th Cir. 1975))). Further, Raduechel’s allegations do not
sufficiently show the statements of PFS officers created oral contracts or warrant
promissory estoppel because the alleged statements, at most, restated the terms of
Raduechel’s written compensation agreement. See Blackledge v. Puncture Proof
Retread Co., 

, 663-64 (Iowa 1921) (stating, an “oral contract must be
independent in fact, and must not be a contradiction, modification, or qualification of
the written contract, either as to its enforcement, its consideration, or its executory
obligation”); Schoff v. Combined Ins. Co. of Am., 

, 48 (Iowa 1999)
(explaining promissory estoppel should be used when a contract does not exist and

                                         -26-
there is “a clear and definite oral agreement” (internal marks and citations omitted)).
We agree with the district court’s analysis; therefore, the district court did not err in
dismissing Raduechel’s counterclaim.

              2.      Motion for Summary Judgment
       Raduechel and Spain also argue the district court erred in granting PFS partial
summary judgment as to Raduechel’s and Spain’s liability on the breach of fiduciary
duties and misappropriation of trade secrets claims. Because we affirm the district
court’s judgment upholding the jury verdict in favor of Raduechel and Spain on these
claims and find PFS was not entitled to a new trial, Raduechel and Spain have
conceded this issue is essentially moot, and we need not address the issue further.3
See Hickman v. Missouri, 

, 1142 (8th Cir. 1998) (“‘When a case . . . no
longer presents an actual, ongoing case or controversy, the case is moot and the
federal court no longer has jurisdiction to hear it.’ This requirement applies to all
stages of the litigation.” (quoting and citing Neighborhood Transp. Network, Inc. v.
Pena, 

, 1172 (8th Cir. 1994))).




      3
       Regardless, Raduechel’s and Spain’s challenge to the district court’s grant of
summary judgment was waived when (1) Raduechel and Spain did not introduce their
arguments to the district court until their motion for reconsideration of the district
court’s grant of summary judgment, and (2) the district court did not address the
arguments on the motion to reconsider. See Anderson, 52 F.3d at 765 (declining to
address an argument which was raised in the district court for the first time in a
motion for reconsideration and which was not adjudicated by the district court).

                                          -27-
III.   CONCLUSION
       The district court’s rulings and judgment are affirmed.
                        ______________________________




                                        -28-