F I L E D
                                                                 United States Court of Appeals
                                                                         Tenth Circuit
                    UNITED STATES CO URT O F APPEALS
                                                                       January 8, 2007
                                   TENTH CIRCUIT                     Elisabeth A. Shumaker
                                                                         Clerk of Court
                          _________________________

M ARIPOSA FARM S, LLC,

             Plaintiff-Appellee,                     No. 05-2344
v.                                              (D.C. No. CIV-03-0779)
                                                      (D. N.M )
W ESTFALIA -SURGE, IN C.,

             Defendant-Appellant.

                           ________________________

                           OR D ER AND JUDGM ENT *
                          _________________________

Before L UC ER O, SILER, ** and O’BRIEN, Circuit Judges.
                       _________________________

      W estfalia-Surge, Inc. (“W estfalia”) appeals the district court’s denial of its

motion for judgment as a matter of law, or in the alternative, for a new trial. For

the following reasons, we AFFIRM .

                                   I. BACKGROUND

      In July 2003, M ariposa Farms, Inc. (“Mariposa”) filed suit against

W estfalia alleging negligence and breach of warranty resulting from the



      *
       This order and judgment is not binding precedent, except under the
doctrines of law of the case, res judicata, and collateral estoppel. It may be cited,
however, for its persuasive value consistent with Fed. R. App. P. 32.1 (eff. Dec.
1, 2006) and 10th Cir. R. 32.1 (eff. Jan. 1, 2007).
      **
        The Honorable Eugene E. Siler, Jr., Senior United States Circuit Judge for
the Sixth Circuit, sitting by designation.
installation and operation of cow-milking equipment manufactured by W estfalia.

M ariposa alleged that the equipment malfunction created unstable vacuum

pressure, which eventually caused mastitis to spread throughout its herd.

      At trial, M ariposa expert witness Dr. Sybren Reitsma testified that, based

on photographs and conversations with M ariposa’s principal manager Larry

Skelley, it was his expert opinion that the design and installation of W estfalia’s

vacuum system caused the unstable vacuum pressure which led to the mastitis

outbreak. Another M ariposa expert witness, Dr. Robert Corbett, opined that the

milking machine equipment malfunction caused the mastitis spread because, in

his experience, the bacteria could not spread as rapidly as it did without the

presence of a milking machine malfunction.

      The jury found W estfalia thirty percent liable and apportioned damages

accordingly. W estfalia filed a motion for judgment as a matter of law, or in the

alternative, for a new trial. In denying both motions, the district court admitted

that it erred in permitting the testimony of Dr. Reitsma because rather than basing

his opinion on test results that he identified as the only reliable and acceptable

means by which to measure vacuum pressure and function, he based his opinion

on photographs of the machine and conversations with the dairy’s manager.

However, the district court still denied both W estfalia motions, finding that

sufficient evidence remained to support the verdict and that the error did not

adversely affect a substantial right of W estfalia. W estfalia now appeals.

                                          -2-
                                  II. DISCUSSION

              A. W estfalia’s M otion for Judgment as a M atter of Law

      W estfalia contends that judgment as a matter of law in its favor is

appropriate because insufficient evidence of causation remains once Dr.

Reitsma’s testimony is properly excluded. It argues that Dr. Corbett provided the

only other causation evidence, but that his testimony should also have been

excluded for the same reasons as Dr. Reitsma’s testimony.

      W e review de novo the denial of a motion for judgment as a matter of law.

M iller v. Eby Realty Group LLC, 

, 1110 (10th Cir. 2005). All

reasonable inferences are draw n in favor of the nonmoving party, and the jury’s

verdict w ill be set aside only if the evidence points but one way. M inshall v.

M cGraw Hill Broad. Co., 

, 1279 (10th Cir. 2003).

      W estfalia asserts that Dr. Corbett’s expert testimony should have been

excluded because his method for determining the existence of a defect in the

milking machine w as unreliable under Daubert v. M errell Dow Pharmaceuticals,

Inc., 

(1993), and Kumho Tire Co., Ltd. v. Carmichael, 

(1997), because it was not based on the generally accepted standards promulgated

by the American Society of Agricultural Engineers (“ASAE”).

      W e review the manner in w hich the district court exercised its Daubert

“gatekeeping” role for an abuse of discretion. General Elec. Co. v. Joiner, 

, 139 (1997). “U nder Daubert’s reliability prong, ‘an inference or

                                          -3-
assertion must be derived by the scientific method . . . [and] must be supported by

appropriate validation – i.e., “good grounds,” based on what is known.’”

Hollander v. Sandoz Pharm. Corp., 

, 1205 (10th Cir. 2002)

(quoting 

). The basis question is whether the expert used

“the methods and procedures of science,” 

, and “the

level of intellectual rigor of the expert in the field.” Kum ho 

.

       In this case, Dr. Corbett’s use of a process known as reasoning to the best

inference to arrive at his conclusions was sufficiently reliable under Daubert and

Kumho, and the district court did not abuse its discretion in admitting his

testimony. Dr. Corbett review ed the lab reports indicating an unusually rapid

spread of mastitis, analyzed M ariposa’s management and maintenance of the dairy

farm, and used his expertise to deduce that the milking system defect caused the

mastitis outbreak. Specifically, he opined that while mastitis could spread in

properly-functioning milking machines, the mastitis could not spread so rapidly as

it did here unless there was a malfunction.

       W estfalia urges that because Dr. Reitsma identified testing pursuant to

ASA E standards as the generally accepted method to discover milking machine

defects, anything else, including Dr. Corbett’s method of reasoning to the best

inference, is unreliable. How ever, as Daubert explicitly recognizes:




                                          -4-
      “General acceptance” is not a necessary precondition to the
      admissibility of scientific evidence under the Federal Rules of
      Evidence, but the Rules of Evidence – especially Rule 702 – do not
      assign to the trial judge the task of ensuring that an expert’s
      testimony both rests on a reliable foundation and is relevant to the
      task at hand. Pertinent evidence based on scientifically valid
      principles will satisfy those demands.

.

      Here, Dr. Corbett’s testimony was based on a scientifically valid method,

see Bitler v. A.O. Smith Corp., 

, 1124 (10th Cir. 2004) (finding

reasoning to the best inference reliable under Daubert and Kumho), and the

district court was proper in admitting it.

      Therefore, the district court properly denied W estfalia’s motion for

judgment as a matter of law because Dr. Corbett’s testimony provided sufficient

causation evidence from which a jury could conclude that W estfalia was

negligent.

                       B. W estfalia’s M otion for a New Trial

      W estfalia next argues that the district court improperly denied its motion in

the alternative for a new trial despite its own acknowledged error in admitting Dr.

Reitsma’s testimony. It contends that Dr. Reitsma’s testimony was impermissibly

prejudicial because, given his qualifications and experience, it had a significant

impact on the jury’s verdict.

      W e review the denial of a motion for a new trial for an abuse of discretion.

Skaggs v. Otis Elevator Co., 

, 514 (10th Cir. 1998). A new trial w ill

                                             -5-
only be granted if the district court “made a clear error of judgment or exceeded

the bounds of permissible choice in the circumstances.” Sheets v. Salt Lake

County, 

, 1390-91 (10th Cir. 1995) (quoting Hinds v. General

M otors Corp., 

, 1046 (10th Cir. 1993)).

      Erroneous admission of expert testimony does not require setting aside the

jury verdict unless the evidence caused actual prejudice and affected a substantial

right. Fed. R. Civ. P. 61; Praseuth v. Rubbermaid, Inc., 

, 1253

(10th Cir. 2005). W e have held that “[e]rroneous admission of evidence is

harmless only if other competent evidence is ‘sufficiently strong’ to permit the

conclusion that the improper evidence had no effect on the decision.” Goebel v.

Denver & Rio Grande W. R.R. Co., 

, 1089 (1st Cir. 2000) (citing

Lillie v. United States, 

, 1192 (10th Cir. 1992)).

      W estfalia argues that the district court erred because it did not apply the

“sufficiently strong/no effect” harmless error standard to determine the effect of

Dr. Reitsma’s testimony on the verdict. It takes issue with the district court’s

statement in the order denying W estfalia’s motion for a new trial that:

      The Court readily acknowledges that, absent Dr. Reitsma’s
      testimony, there is decidedly less evidence in the record for the jury
      to have properly relied upon in finding liability on the part of the
      Defendant . . ., [but] the Court finds sufficient evidence remains in
      the record to support the verdict and that the Court’s error in
      allowing Reitsma’s testimony did not adversely affect a substantial
      right of Defendant.




                                         -6-
      As discussed above, Dr. Corbett’s testimony provided the jury with

sufficient evidence to find that W estfalia w as negligent and breached its

warranties. He studied the milking machine, M ariposa’s management, and

through the logic of best inference, reasonably deduced that the milking machine

was defective because he had never seen a mastitis outbreak spread so rapidly

where defective equipment was not the culprit. This methodology was reliable

and provides a sufficient basis to conclude that the milking machine was

defective. The jury also heard corroborating lay testimony of several witnesses,

including W estfalia dealer Jerry Danforth and engineer Graeme M ein, who

testified that the vacuum regulator was improperly installed and could result in

vacuum and pulsation problems.

      The district court was in the best position to determine the effect of Dr.

Reitsma’s testimony and its analysis did not abdicate its role in properly gauging

its effect. Given that Dr. Corbett testified as to causation, and that his testimony

was supported by other witnesses, the denial of W estfalia’s motion was not an

abuse of discretion.

      AFFIRM ED.



                                                Entered for the Court,


                                                Eugene E. Siler, Jr.
                                                Senior United States Circuit Judge

                                          -7-