United States Court of Appeals
                           FOR THE EIGHTH CIRCUIT
                                    ___________

                                    No. 10-2124
                                    ___________

John E. Knudson,                         *
                                         *
             Plaintiff - Appellant,      *
                                         * Appeal from the United States
      v.                                 * District Court for the
                                         * Western District of Missouri.
Systems Painters, Inc.; Systems Painters *
& Drywall, LP; Systems Painters &        *
Drywall II, LP,                          *
                                         *
             Defendants - Appellees.     *
                                    ___________

                              Submitted: January 11, 2011
                                 Filed: March 10, 2011
                              Amended: March 11, 2011
                                  ___________

Before MURPHY, BYE, and MELLOY, Circuit Judges.
                           ___________

MELLOY, Circuit Judge.

       John E. Knudson alleges he suffered lung injuries while working on a
construction site after he inhaled a significant amount of paint particulate. To recover
damages, Knudson brought state-law claims in an action in Missouri state court
against Randy Long, Systems Painters, Inc., Systems Painters & Drywall, LP, and
Systems Painters & Drywall II, LP. (We refer to the last three defendants as a single
entity, "Systems Painters.") Knudson alleges that Long was a co-employee who
supervised him at the construction site and that Systems Painters produced the paint
particulate at issue. Knudson and Systems Painters agree that Knudson and Long are
Missouri citizens and that Systems Painters is a Texas citizen.1

       The Missouri circuit court dismissed Knudson's claim against Long, finding that
Missouri's workers' compensation laws provided Long with immunity. Systems
Painters then removed the action to the U.S. District Court for the Western District of
Missouri. Knudson sought remand, arguing that Long's presence prevented diversity
of citizenship. The court denied Knudson's remand motion after finding that he had
fraudulently joined Long. However, the court proceeded no further in resolving
Knudson's claims against Systems Painters. Instead, the court certified its order
denying remand for interlocutory appeal pursuant to 28 U.S.C. § 1292(b). Knudson
applied for an interlocutory appeal, we granted his application, and we now reverse.

                                    I. Background

      Knudson is a former employee of Long Refrigeration, Inc., a Missouri
corporation. In 2003, Wal-Mart decided to build stores in Ava and Ozark, Missouri.
Wal-Mart awarded the construction contracts to two separate companies, with each
company hiring Long Refrigeration to install heating, ventilating, and air-conditioning
("HVAC") systems for each of the stores. Additionally, each company hired Systems
Painters to paint the stores' interiors.

       Long Refrigeration began installing the HVAC systems in December of 2003
or 2004. During this same time, Systems Painters began painting. Knudson claims
that Systems Painters was supposed to apply its paints and coatings only in "well-
ventilated area[s]" and that individuals who were working nearby were supposed to

      1
         Because of our disposition of the case, we do not need to decide whether the
parties' agreement on this issue is sufficient. See Ark. Blue Cross & Blue Shield v.
Little Rock Cardiology Clinic, P.A., 

, 816 (8th Cir. 2009) (noting that
parties cannot waive or consent to subject-matter jurisdiction).

                                         -2-
have proper equipment to prohibit the inhalation of paint particulate. Knudson claims,
however, that the construction sites were "unventilated" and that his equipment did
not effectively prevent the inhalation of paint particulate. Specifically, Knudson
claims Systems Painters covered the openings of the stores with plastic "to minimize
the availability of fresh air" and then used heaters to apply the paint at an elevated
temperature. These actions "essentially shrink-wrapped" the stores, according to
Knudson. As a result, the paint particulate in the air was so thick that Knudson and
others who were installing the HVAC systems would "have difficulty seeing what
they were working on," would "leave the job site completely coated" in paint, and
would have "difficulty breathing."

       While working on the HVAC installations, Knudson claims he was "operating
under the direct management and control" of Long. Knudson claims he and other
Long Refrigeration employees told Long that they were having difficulty breathing
and working in the stores as a result of the paint particulate in the air. In response,
according to Knudson, Long "demanded" that Knudson and the other employees "get
into the [stores] and complete the HVAC contract" because Long Refrigeration did not
want to pay any penalties for failing to complete the HVAC systems on time. Long
provided the employees with masks, but Knudson claims these were "cheap and
inadequate" and became "so clogged with particulate matter [that the employees]
would have to remove them in order to be able to breath at all." As a result, Knudson
had to inhale paint particulate. According to Knudson, this caused "severe,
permanent, and disabling injury to his lungs" and "a severe loss of lung capacity" that
has "rendered [him] permanently and totally disabled from any gainful employment."

      On August 25, 2005, Knudson filed a claim for his lung injuries with Missouri's
Division of Workers' Compensation. On July 1, 2008, Knudson filed a suit against
Long and Systems Painters in Missouri state court. Knudson claimed that the conduct
of both Long and Systems Painters caused his lung injuries. Missouri's workers'
compensation laws ordinarily immunize co-employees like Long from negligence

                                         -3-
liability for failing to maintain a safe working environment, but co-employees may be
liable for damages caused by "affirmative acts of negligence" outside the scope of an
employer's responsibility to provide a safe workplace. Thus, Knudson alleged that
Long committed affirmative acts of negligence by providing inadequate breathing
masks and by instructing him to continue installing the HVAC systems despite
knowing that the construction sites were very poorly ventilated. Knudson claimed
these actions were "deliberate[], intentional[], and in conscious disregard for [his]
safety."

       On October 14, 2008, Long filed a motion to dismiss, arguing that he was
immune from suit because Knudson's allegations were insufficient to establish that
Long had committed an affirmative act of negligence. On November 5, the Missouri
circuit court granted the motion.

       On December 4, 2008, Systems Painters removed the case to the U.S. District
Court for the Western District of Missouri. On December 29, Knudson filed a motion
to remand, arguing that because Long is a Missouri citizen, "there [was] not complete
diversity of citizenship at the time of the filing of this matter in [Missouri state court]."
On April 5, 2009, the district court issued an order denying Knudson's motion to
remand. The court found that it had original jurisdiction based upon diversity of
citizenship because Knudson had fraudulently joined Long.

       In this interlocutory appeal, Knudson argues that the district court erred in
denying his motion to remand because (1) Systems Painters's notice of removal was
not timely and (2) the district court lacked original jurisdiction over this case.




                                            -4-
                                   II. Discussion

               A. Whether Systems Painters's Removal Was Timely

       Knudson first argues that the district court erred in denying his remand motion
because Systems Painters's notice of removal was not timely. The removal statutes
provide a thirty-day deadline by which a defendant must file a notice of removal. 28
U.S.C. § 1446(b). The event that triggers the running of this thirty-day deadline
depends upon whether "the case stated by the initial pleading" is removable. 

agree that this case, as "stated by the initial pleading," was not removable.
Thus, the running of the thirty-day deadline was triggered when—and if—Systems
Painters received "through service or otherwise, . . . a copy of an amended pleading,
motion, order, or other paper from which it may first [have been] ascertained that the
case is one which is or has become removable." 

court ruled that Systems Painters's notice of removal was timely,
and we review this ruling de novo. Lovern v. Gen. Motors Corp., 

, 161
(4th Cir. 1997).

      On appeal, Knudson argues that when Systems Painters received Knudson's
complaint on July 1, 2008, it could have ascertained that the case was removable
because it could have ascertained that diversity of citizenship existed2 and that the
amount-in-controversy requirement was met. Systems Painters argues that it could
not ascertain whether Knudson's action satisfied the amount-in-controversy
requirement until November 13, 2008, when it received records from Missouri's


      2
       According to Knudson, assuming arguendo that he fraudulently joined Long,
Systems Painters could have ascertained this by looking at his complaint.
Consequently, according to Knudson, Systems Painters could have ascertained by
looking at Knudson's complaint that there was diversity of citizenship among the non-
fraudulently joined parties.

                                         -5-
Department of Workers' Compensation which quantified some of Knudson's alleged
damages. In response, Knudson argues that even though his complaint did not
explicitly state that the case met the amount-in-controversy requirement, Systems
Painters had to "glean from the general allegations of damages [in his complaint]
whether a jury could conceivably render a verdict in excess of $75,000." Knudson
argues that since he alleged in his complaint that he suffered permanent lung damage
and that he will be unable to be gainfully employed in the future, it is apparent that a
jury could conceivably render a verdict in his favor in excess of $75,000.

       This case raises a similar issue to the one we faced in In re Willis, 

(8th Cir. 2000). In that case, a Missouri plaintiff brought a personal-injury action
against a Virginia defendant in Missouri state court. 

The plaintiff sought
damages for pain and suffering, permanent disability, and wage loss, but the plaintiff's
complaint did not explicitly disclose the amount of damages sought. The defendant
removed the case to federal court. The plaintiff filed a motion to remand, arguing that
the defendant's removal was untimely because he filed his removal notice more than
thirty days after he received a copy of the plaintiff's complaint. 

       We disagreed that the defendant's removal was untimely and stated, "We find
the thirty-day time limit of section 1446(b) begins running upon receipt of the initial
complaint only when the complaint explicitly discloses the plaintiff is seeking
damages in excess of the federal jurisdictional amount." 

see also Moltner
v. Starbucks Coffee Co., 

, 38 (2d Cir. 2010) (approvingly citing In Re
Willis and stating that the Second Circuit "join[s] the Eighth Circuit . . . in holding
that the removal clock does not start to run until the plaintiff serves the defendant with
a paper that explicitly specifies the amount of monetary damages sought"). This rule,
we noted, "'promotes certainty and judicial efficiency by not requiring courts to
inquire into what a particular defendant may or may not subjectively know.'" In re

(quoting Chapman v. Powermatic, Inc., 

, 163 (5th
Cir. 1992)).

                                           -6-
       Thus, in In re Willis, we rejected Knudson's argument that Systems Painters had
to "glean" the amount in controversy from Knudson's complaint. See also 

(rejecting argument that the "removal clock runs from the service of
the complaint, even where the complaint does not specify the amount of monetary
damages sought, when the defendant can reasonably discern from the complaint that
the damages sought will meet the amount-in-controversy requirement"). Knudson
notes that Missouri Rule of Civil Procedure 55.19 prohibits him from explicitly stating
the amount in controversy in his complaint. However, the plaintiffs in In re Willis and
Moltner faced the same restriction. Moreover, despite this restriction, there were other
ways Knudson could have triggered the running of § 1446(b)'s thirty-day deadline.
See 28 U.S.C. § 1446(b) (noting that the defendant's receipt, "through service or
otherwise, of a copy of an amended pleading, motion, order, or other paper" triggers
the running of the thirty-day deadline).

       Therefore, since Knudson's complaint did not explicitly state the amount in
controversy, Knudson's complaint did not trigger the running of § 1446(b)'s thirty-day
deadline. Knudson points to no other event that triggered the running of the deadline
that would have made Systems Painters's notice of removal untimely.3 Thus, the
district court did not err in finding that Systems Painters's removal notice was timely.

              B. Whether the District Court Had Original Jurisdiction

       Knudson next argues that the district court erred in denying his remand motion
because the court lacked jurisdiction over the case. Section 1441(a) allows a
defendant to remove an action pending in state court to a federal district court that has
"original jurisdiction" over the action. The district court ruled that it had original


      3
        We express no opinion regarding whether Systems Painters's receipt of records
from Missouri's Division of Workers' Compensation on November 13, 2008, triggered
the running of § 1446(b)'s thirty-day deadline. Even if it did, Systems Painters filed
its removal notice well within thirty days of this date.
                                         -7-
jurisdiction over the case, so it denied Knudson's motion to remand. We review de
novo a district court's denial of a motion to remand for lack of original jurisdiction.
Kirkland v. Wyeth (In re Prempro Prods. Liab. Litig.), 

, 619 (8th Cir.
2010). Systems Painters bears the burden of establishing that the district court had
original jurisdiction by a preponderance of the evidence. 

"All doubts about
federal jurisdiction should be resolved in favor of remand to state court." Junk v.
Terminix Int'l Co., 

, 446 (8th Cir. 2010) (internal quotation marks
omitted).

        Systems Painters argues that the district court had original jurisdiction over this
case pursuant to 28 U.S.C. § 1332(a)(1). That statute vests district courts with
"original jurisdiction" over civil cases where the amount in controversy exceeds
$75,000 and where the case is between citizens of different states. § 1332(a)(1). "In
the case of a removed action, diversity [of citizenship] must exist both when the state
petition is filed and when the petition for removal is filed."4 Ryan ex. rel. Ryan v.
Schneider Nat'l Carriers, Inc., 

, 819 (8th Cir. 2001) (citing Koenigsberger
v. Richmond Silver Mining Co., 

, 49–50 (1895)); see also Gibson v.
Bruce, 

, 563 (1883); MacGinnitie v. Hobbs Grp., LLC, 

,
1239–40 (11th Cir. 2005); Strotek Corp. v. Air Transp. Assoc. of Am., 

,
1131–32 (9th Cir. 2002); Kanzelberger v. Kanzelberger, 

, 776–77 (7th
Cir. 1986). According to the Supreme Court, the rationale for this time-of-filing rule
is to prevent defendants from manipulating jurisdiction by changing their citizenship
after the plaintiff has filed its suit in state court. 

. As applied
to this case, this rule would mean that the district court did not have original
jurisdiction pursuant to § 1332(a)(1), because at the time Knudson filed his complaint
in Missouri state court, Long's citizenship destroyed diversity of citizenship.



      4
          Federal courts apply a similar time-of-filing rule when the plaintiff initially
files its suit in federal district court rather than state court. Freeport-McMoRan, Inc.
v. K N Energy, Inc., 

, 428 (1991).
                                              -8-
       There are at least two exceptions to this time-of-filing rule, however. First,
pursuant to Powers v. Chesapeake & Ohio Ry. Co., if the plaintiff voluntarily
dismisses the diversity-destroying defendant, a defendant may then be able to remove
the case. 

, 101–02 (1898); see In re Iowa Mfg. Co., 

, 463
(8th Cir. 1984) (citing Powers and noting the existence of the exception); see also
McCord v. Minn. Mut. Life Ins. Co. (In re Minn. Mut. Life Ins. Co. Sales Practice
Litig.), 

, 834 (8th Cir. 2003) (affirming a district court's finding that it
had original jurisdiction over a removed case where the plaintiff voluntarily dismissed
the diversity-destroying defendant). The rationale for this exception is not entirely
clear, but commentators suggest that when a plaintiff voluntarily dismisses a diversity-
destroying defendant, the justification for the time-of-filing rule is not present. 14B
Charles Alan Wright & Arthur R. Miller, Federal Practice and Procedure § 3723 (4th
ed. 2009). This is because a defendant generally has no control over whether the
plaintiff voluntarily dismisses another defendant, so there is no risk that a defendant
has changed its citizenship to manipulate jurisdiction.5

       The second exception to the time-of-filing rule is the fraudulent-joinder
exception. Under this exception, a plaintiff cannot defeat a defendant's "right of
removal" by fraudulently joining a defendant who has "no real connection with the
controversy." Chesapeake & Ohio Ry. Co. v. Cockrell, 

, 152 (1914); see
also Simpson v. Thomure, 

, 1083 (8th Cir. 2007) ("[T]he right of an
out-of-state defendant to remove a diversity suit to federal court 'cannot be defeated
by a fraudulent joinder of a resident defendant.'" (quoting Wilson v. Republic Iron &
Steel Co., 

, 97 (1921))). The purpose of this exception is to strike a
balance between the plaintiff's right to select a particular forum and the defendant's
right to remove the case to federal court. Wright & Miller, supra, § 3723.


      5
        Commentators have offered other rationales for the voluntary-dismissal
exception. See e.g., E. Farish Percy, Making a Federal Case of It: Removing Civil
Cases to Federal Court Based on Fraudulent Joinder, 

. Rev. 189, 207–11
(2005) (discussing several potential rationales).
                                          -9-
      In this case, Systems Painters argues that both exceptions to the time-of-filing
rule apply. The district court ruled that the voluntary-dismissal exception did not
apply, but that the fraudulent-joinder exception did. We next consider whether these
rulings were correct.

                         i. The Voluntary-Dismissal Exception

       Systems Painters first argues that Powers's voluntary-dismissal exception to the
time-of-filing rule applies in this case. The district court rejected this argument,
finding that Long's dismissal was "undoubtedly involuntary" as to Knudson. While
Systems Painters concedes that the dismissal of Long was "initially involuntary," it
argues that Knudson "transformed" this dismissal into a voluntary one by not seeking,
inter alia, a writ of mandumus or a certification of the order for interlocutory appeal.

        Generally, courts have suggested that a dismissal is voluntary as to a plaintiff
only if the plaintiff "initiated the dismissal." Poulos v. Naas Foods, Inc., 

,
72 n.3 (7th Cir. 1992) (citing Self v. Gen. Motors Corp., 

, 658 (9th Cir.
1978) (noting that pursuant to Powers and Whitcomb v. Smithson, 

(1900), "only a voluntary act of the plaintiff could bring about removal to federal
court")). When the diversity-destroying defendant initiates its own dismissal, and
when the court's order is against the will of the plaintiff, the dismissal is not voluntary.

. In this case, Long filed a motion to be dismissed from
the case, and Knudson filed a memorandum in opposition to Long's motion. Thus, the
court's order dismissing Long was initiated by Long, and it was entered against
Knudson's will. Therefore, the court's dismissal of Long was involuntary—at least
initially—as to Knudson.

       The Second Circuit has held that a plaintiff's post-dismissal action (or inaction)
can transform an initially involuntary dismissal into a voluntary one. In Quinn v.
Aetna Life & Cas. Co., the court held that a plaintiff's failure to appeal a state court's
order dismissing diversity-destroying defendants upon the diversity-destroying
                                         -10-
defendants' motion could transform an involuntary dismissal into a voluntary one.

, 40 n.2 (2d Cir. 1980). Contra Insinga v. LaBella, 

, 252
(11th Cir. 1988) (rejecting Quinn's holding that a plaintiff's failure to timely appeal
a dismissal order makes an initially involuntary dismissal a voluntary one). However,
it is unclear whether the plaintiff in Quinn took steps to oppose the diversity-
destroying defendants' motion prior to the state court's order, as Knudson did.
Moreover, unlike the plaintiff in Quinn, Knudson filed a timely appeal of the order
dismissing Long, although the Missouri Court of Appeals dismissed the appeal as
interlocutory.6 Thus, since this case is distinguishable from Quinn, and since Systems
Painters cites no other authority for the proposition that a plaintiff's actions can
transform an involuntary dismissal into a voluntary one, Systems Painters has failed
to prove that Knudson voluntarily dismissed Long for purposes of the Powers
exception.

                         ii. The Fraudulent-Joinder Exception

       Systems Painters next argues that the fraudulent-joinder exception to the time-
of-filing rule applies in this case. The district court agreed, and Systems Painters
urges us to affirm this finding.

               a. Determining the Proper Fraudulent-Joinder Standard

      The first issue we must consider is what standard we should apply to determine
whether Knudson fraudulently joined Long. Ordinarily, to prove that a plaintiff
fraudulently joined a diversity-destroying defendant, we have required a defendant
seeking removal to prove that the plaintiff's claim against the diversity-destroying


       6
        Generally, orders like the one dismissing Long are not appealable because
they do not dispose of "all the issues for all parties in the case" such that nothing is left
for future determination. Mo. Sup. Ct. R. 74.01(b); Fleahman v. Fleahman, 

, 164 (Mo. Ct. App. 1999).
                                            -11-
defendant has "no reasonable basis in fact and law." Filla v. Norfolk S. Ry. Co., 

, 810 (8th Cir. 2003) (internal quotation marks omitted).7 In spite of this rule,
Systems Painters argues that because the Missouri circuit court dismissed Long for
"lack of subject matter jurisdiction," we should automatically find that Knudson
fraudulently joined Long. Alternatively, Systems Painters cites Simpson v. Thomure,

(8th Cir. 2007) and argues that we should apply a Rule 12(b)(6)
standard—rather than Filla's standard—to determine whether Knudson fraudulently
joined Long.8

       We first reject Systems Painters's argument that the Missouri state court's
dismissal of Long requires us to find that Knudson fraudulently joined him. In the
Eleventh Circuit case of Insinga v. LaBella, a plaintiff sued a non-diverse defendant
and a diverse defendant in state 

. The state court dismissed the
non-diverse defendant "based on sovereign immunity," and pursuant to state law, such
determinations were jurisdictional. 

In deciding whether the defendant's
removal was proper, the court stated,

      For all intents and purposes, a trial court's finding that it lacks
      jurisdiction over a resident defendant is akin to a finding of fraudulent
      joinder of that defendant in that it involves a determination by the court
      that the resident defendant was never properly before the court, rather



      7
         In Simpson v. Thomure, 

, 1084 n.2 (8th Cir. 2007), we
questioned our jurisdiction in Filla. However, we applied the Filla standard in other
cases prior to Simpson. See e.g., Menz v. New Holland N. Am., Inc., 

,
1004 (8th Cir. 2006). And, since Simpson, we have continued to apply the Filla
standard. See 

. Thus, the Filla standard remains good law in
this circuit.
      8
         It is somewhat unclear what standard the district court applied in determining
that Knudson fraudulently joined Long. The court did not cite Filla or allude to the
Filla standard. Instead, the court analyzed Knudson's allegations in his pleadings.
Thus, it seems the court applied something akin to a Rule 12(b)(6) standard.
                                         -12-
      than a determination that the court had jurisdiction of that defendant but
      that the case against him, although not frivolous, was not meritorious.

Systems Painters argues that, under Insinga, a state court's
dismissal of a non-diverse defendant for lack of jurisdiction requires a federal court
to find that the plaintiff fraudulently joined that defendant. Since the Missouri circuit
court dismissed Long for "lack of subject matter jurisdiction," Systems Painters argues
that we should apply this per se rule and find that Knudson fraudulently joined Long.

        We decline to apply a per se rule based upon Insinga for at least three reasons.
First, the court in Insinga seemed to incorrectly suggest that whether a plaintiff has
fraudulently joined a defendant is a question of state law. See 

to sustain
a fraudulent joinder, a state court must find either that there was no possibility that the
plaintiff could prove a cause of action against the resident defendant or that the
plaintiff fraudulently pled jurisdictional facts . . . ." (emphasis added)). Although the
question of whether a plaintiff has fraudulently joined a defendant requires a close
analysis of state law, this question is ultimately one of federal law. See 

n.4 (noting that federal courts are not bound by a state-court judgment
when deciding whether a plaintiff fraudulently joined a defendant). Second, the
Insinga court's suggestion that a per se rule would be appropriate was merely dictum.
See 

n.4 ("We do not mean to imply that the [diversity-
destroying defendant] was fraudulently joined in this case, nor do we need to make
that determination in light of our disposition of the case."). Finally, since Long's
dismissal, the Missouri Supreme Court has clarified that a dismissal due to a
defendant's immunity under the state's workers' compensation laws is not a dismissal
for lack of jurisdiction.9 See McCracken v. Wal-Mart Stores E., LP, 

,


      9
        Systems Painters contends that McCracken applies only prospectively. Prior
to McCracken, defendants seeking immunity under the state's workers' compensation
laws could file a motion for lack of subject-matter jurisdiction at any time. In
McCracken, the Missouri Supreme Court held that such a defense was waived unless
asserted as an affirmative defense. The court stated, however, that "[b]ecause recent
                                        -13-
477 (Mo. 2009) (en banc). Thus, the rationale for Insinga's per se rule (to the extent
Insinga, in fact, created one) is not present here. For these reasons, we decline
Systems Painters's request to find that Knudson fraudulently joined Long solely
because the Missouri circuit court dismissed him due to immunity provided by the
state's workers' compensation laws.

       We also reject Systems Painters's argument that Simpson requires us to apply
a Rule 12(b)(6) standard—rather than the Filla standard—to determine whether
Knudson's fraudulently joined Long. In Simpson, a Missouri plaintiff was injured in
the course of her employment while operating a power 

. She
brought an action in Missouri state court against the diverse power-press manufacturer
and her non-diverse workplace supervisor. The manufacturer removed the case to
federal court. The plaintiff sought remand on the basis of her supervisor's citizenship.
Although the plaintiff was aware that Missouri's workers' compensation laws normally
immunize co-workers for workplace negligence, the plaintiff argued that her claim
met the same exception to this rule that Knudson argues applies in this case. The
district court, however, ruled that the exception was not met, denied remand, and held
that the plaintiff fraudulently joined her supervisor. Moreover, since the plaintiff
could not state a claim against her supervisor, the court dismissed the supervisor
pursuant to Rule 12(b)(6). Four months later, the remaining parties settled, so the
court entered final judgment in the case. 

       On appeal, rather than applying the Filla standard to consider whether the
plaintiff had fraudulently joined her supervisor, we considered whether the federal
district court had properly ruled on the supervisor's Rule 12(b)(6) motion. This


cases erroneously suggested that the [Workers' Compensation Law]'s applicability
could be raised by filing a motion to dismiss for lack of subject matter jurisdiction,
 . . . , this rule will be applied prospectively only." 

.
By our reading, the only aspect of McCracken that applies prospectively is the
requirement that a defendant assert its immunity under the state's workers'
compensation law as an affirmative defense.
                                             -14-
analysis was warranted, we explained, because of the "present procedural posture of
the case." 

      At this time, final judgment has been entered, so there is nothing to
      remand to state court unless the district court’s Rule 12(b)(6) dismissal
      of [plaintiff’s] claim against [the supervisor] is reversed. If that claim is
      revived, remand will follow automatically because [plaintiff and her
      supervisor], the only remaining defendant, are citizens of the same state.
      Thus, the significant issue on appeal is whether the district court erred
      in dismissing the claim against [the supervisor] on the merits.

held that the district court did not err in dismissing plaintiff’s claim
against her supervisor pursuant to Rule 12(b)(6). 

       Thus, in Simpson, we reviewed the district court's ruling on the supervisor's
Rule 12(b)(6) claim, not the district court's ruling on the diverse power-press
manufacturer's claim that the plaintiff fraudulently joined the supervisor. The
"procedural posture" of the case—not the fact that the plaintiff may have fraudulently
joined a party who enjoyed immunity under the state's workers' compensation
laws—justified the analysis in Simpson. See Council Tower Assoc. v. Axis Speciality
Ins. Co., 

, 730–31 (8th Cir. 2011) (applying the Simpson analysis for the
same procedural-posture reasons even though the allegedly fraudulently joined,
diversity-destroying defendant did not claim to be protected by a form of immunity);
but see 

(suggesting that the allegedly fraudulently joined,
diversity-destroying defendant's claim to statutory immunity justified the court's
analysis in Simpson). In this case, the procedural posture that existed in Simpson is
not present because the federal district court never entered a final judgment in the
case. Instead, after ruling that Knudson fraudulently joined Long, the court proceeded
no further in resolving the merits of Knudson's claims against Systems Painters and
certified its order denying remand for appeal pursuant to 28 U.S.C. § 1292(b). Thus,




                                          -15-
the Simpson analysis is inapplicable here. As a result, Filla and its progeny provide
the appropriate standard for determining whether Knudson fraudulently joined Long.10

                  b. Application of the Filla Standard in this Case

        As explained earlier, to prove that a plaintiff fraudulently joined a diversity-
destroying defendant, we require a defendant seeking removal to prove that the
plaintiff's claim against the diversity-destroying defendant has "no reasonable basis
in fact and law." 

(internal quotation marks omitted). Under this
standard, "if it is clear under governing state law that the complaint does not state a
cause of action against the non-diverse defendant, the joinder is fraudulent and federal
jurisdiction of the case should be retained." 

marks omitted).
However, joinder is not fraudulent where "there is arguably a reasonable basis for
predicting that the state law might impose liability based upon the facts involved."11

      By requiring the defendant to prove that the plaintiff's claim against the non-
diverse defendant has no reasonable basis in law and fact, we require the defendant
to do more than merely prove that the plaintiff's claim should be dismissed pursuant

      10
          We did express some concern in Simpson with applying the Filla standard
when the allegedly fraudulently joined, diversity-destroying defendant claims to be
immune from suit, but we did not hold that the Filla standard is inapplicable in cases
like this one. 

n.2. Moreover, other courts have applied
standards like the Filla standard when determining whether a plaintiff fraudulently
joined a diversity-destroying defendant who claims immunity pursuant to a state's
workers' compensation laws. See e.g., Jernigan v. Ashland Oil Inc., 

,
815–16 (5th Cir. 1993); Cook v. Pep Boys-Mannie, Moe & Jack, Inc., 

, 45–46 (E.D. Pa. 1985). Thus, we decline to depart from the Filla standard.
      11
         Since the Missouri circuit court in this case dismissed Long, the issue is not
whether there is "any reasonable possibility that a state court would rule against
[Long]," but rather whether there is "any reasonable possibility" that the state court
order dismissing Long "will be reversed on appeal." 

n.4.
                                         -16-
to a Rule 12(b)(6) motion. 

(noting that the Rule 12(b)(6)
standard is "more demanding" than the Filla standard). In this analysis, we do not
focus on the artfulness of the plaintiff's pleadings. Wilkinson v. Shackelford, 

, 964 (8th Cir. 2007).

       Knudson claims that Long is liable in damages for the injuries that Knudson
sustained to his lungs while installing the HVAC systems. In Missouri, when an
employee is injured during the course of employment by an "accident," the employee
can generally only recover damages pursuant to Missouri's workers' compensation
laws. Mo. Rev. Stat. § 287.120. Injured employees generally cannot sue employers
or co-employees for such damages in state court. Burns v. Smith, 

,
337 (Mo. 2007) (en banc). "However, an employee may sue a fellow employee for
affirmative negligent acts outside the scope of an employer's responsibility to provide
a safe workplace." 

(internal quotation marks omitted). Missouri courts call
this the "something more" exception. 

of what constitutes an 'affirmative negligent act' has not proven
susceptible of reliable definition." 

marks omitted). "Courts
have essentially applied the rule on a case-by-case basis with close reference to the
facts in each individual case." 

marks omitted). "[T]he notion
of an affirmatively negligent act—the 'something more'—can best be described as an
affirmative act that creates additional danger beyond that normally faced in the job-
specific work environment." 

have found that supervisors commit affirmative acts of
negligence when they direct employees "to engage in dangerous conditions that a
reasonable person would recognize as hazardous beyond the usual requirements of
employment." Sexton v. Jenkins & Assocs., Inc., 

, 5 (Mo. Ct. App. 2000)
(citing Lyon v. McLaughlin, 

, 526 (Mo. Ct. App. 1998)); see also

(holding that a supervisor committed an affirmative act of
negligence by "intentionally direct[ing] the plaintiff[-employee] to undertake an
                                       -17-
activity that [the] defendant knew would result in a particularly dangerous event");

(noting that, under Missouri law, "a supervisor is not
entitled to his employer's immunity if he directed the plaintiff employee to engage in
dangerous conditions that a reasonable person would recognize as hazardous beyond
the usual requirements of employment" (internal quotation marks omitted)).

       It is not necessary, however, that such a supervisor be responsible for creating
the hazardous condition at issue.12 Groh v. Kohler, 

(Mo. Ct. App.
2004), abrogated on other grounds by 

–39, illustrates this
point. In Groh, the plaintiff's job required operating a machine that would compress
plastic into particular shapes. 

Over time, hardened plastic would
accumulate in the machine and would have to be removed by hand. The plaintiff's
machine began malfunctioning by sporadically compressing on its own. When the
plaintiff told her supervisor, who was the defendant in the case, the supervisor told her
to "quit whining" and to "just deal with it." 

Later, when the plaintiff was
reaching her hand into the machine to remove some hardened plastic, the machine
compressed on its own and injured the plaintiff's hand. The Missouri Court of
Appeals held that the plaintiff had stated a claim for an affirmative act of negligence
because, "[a]lthough [the defendant] is not alleged to have caused the machine to
malfunction, her alleged conduct of compelling [the plaintiff] to continue to perform
her duties by operating the known dangerous machine that was likely to injure the
operator effectively created the dangerous condition resulting in the injuries sustained
by [the plaintiff]." 

(finding defendant supervisor committed an
affirmative act of negligence by directing an employee to operate a concrete mixer
until the employee blew a water-pressure tank which the defendant had welded onto
the mixer); Hedglin v. Stahl Specialty Co., 

(Mo. Ct. App. 1995)
(finding defendant supervisor committed an affirmative act of negligence by directing
an employee to venture onto a makeshift crane which the supervisor had created above
a vat of scalding water).
                                        -18-
       This case is similar to Groh. Knudson's complaint alleges that he was
"operating under the direct management and control" of Long, which is essentially an
allegation that Long was Knudson's supervisor. Knudson further alleges that Long
instructed him to install HVAC systems in construction sites that were very poorly
ventilated. Knudson alleges that he and other employees told Long of the poor
ventilation and of their breathing difficulties. Nonetheless, Knudson alleges that Long
"demanded" that Knudson "get into the [stores] and complete the HVAC contract."
Obviously, Long did not introduce the paint particulate into the air inside the
construction sites, but, like Groh, Long may have "effectively created the dangerous
condition" by ordering Knudson to work in an environment where Long knew the
employees he was supervising were having breathing problems.

       For the foregoing reasons, "there is arguably a reasonable basis for predicting
that [Missouri law] might impose liability" on Long. 

. As a
result, Knudson did not fraudulently join Long. Thus, since Systems Painters has not
proved that an exception to the time-of-filing rule applies, the district court erred in
denying Knudson's motion to remand for lack of original jurisdiction.

                                    III. Conclusion

     For these reasons, we reverse the district court's order denying Knudson's
motion to remand, and we return this case to the district court with instructions to
remand it to state court.
                        ______________________________




                                         -19-