Compliance of expert’s methodology with Federal Rule of Evidence 702 and Daubert- a must for including expert’s opinion

The testimony of an expert witness may be excluded in part if the methodology backing his ultimate opinion does not satisfy the standards set forth in the Federal Rules of Evidence, 702 and Daubert v. Merrell Dow Pharmaceuticals, Inc. [509 U.S. 579,(1993)]. This was held by the United States District Court for the District of Nebraska – Omaha and recently affirmed by the Eight Circuit on appeal in the matter of Union Pacific Railroad Company v. Progress Rail Services Corporation (2015 U.S. App. LEXIS 2114).

The case owes its origin to a rule of Federal law (49 C.F.R. § 215.105.) that prohibits railroads from placing or continuing in service any rail car axles that have certain defects, including cracks and pitting (corrosion of the axle in the form of round pits on the surface of the dust guard, fillet, or journal-components of the outside end of the axle).

 In July 2007 and January 2010, two trains of 135 and 123 loaded coal cars derailed near DeWitt, Iowa and Martin Bay, Nebraska, respectively, on the tracks of Union Pacific Railroad Company due to failed rail car axles which had been reconditioned by Progress Rail Services Corporation. Union Pacific filed a suit against Progress Rail alleging negligent reconditioning of the DeWitt and Martin Bay axles.

The Plaintiff adduced the testimony of its expert – a professional mechanical engineer with a master’s degree and more than twenty-five years of experience in derailment investigation. After examining inter alia the fractured axles, Plaintiff’s expert surmised that the corrosion pits which the Defendant had failed to remove triggered the failure of the rail car axles and the ultimate derailments.

 Although the expert could not identify the corrosion pits which caused the axles to fail, or determine which of the pits developed after Progress Rail reconditioned the axles, in his opinion the fact that they failed within fifteen and five months after being reconditioned bore testimony to the fact that there could have been impairments like pitting, cracking, etc. to indicate that the axles should not have been returned to service.

The Defendant moved in limine to exclude Plaintiff’s expert opinion. The District Court ordered that Union Pacific’s expert would be permitted to testify that certain corrosion pits and fatigue cracks in the axle were present at the time Progress Rail reconditioned them, which it failed to remove and the same could have resulted in the axle failure. The District Court however, did not allow the expert to furnish his ultimate opinion – corrosion pits and/or fatigue cracks present in the axles before they were refurbished by Progress Rail actually caused or more likely than not caused the axle failures since this portion of the opinion was not “supported by methodology that satisfied the standards of the Federal Rule of Evidence, 702 and Daubert.”

The case proceeded to trial, and once again the District Court rejected the ultimate “really pretty narrow” opinion of Plaintiff’s expert since it was not persuaded by any particular methodology described by the expert that he could vouch for with a fair amount of certainty.

 Defendant’s expert testified that the axles had been properly refurbished and their failure was due to some fatigue-inducing mechanism other than corrosion pitting. Plaintiff did not file a motion in limine to exclude Defendant’s expert testimony but it did object to the basis of his opinions at the trial which was overruled by the District Court.

The decision of the District Court to exclude in part the testimony of its expert while admitting the same of the Defendant, prompted the Plaintiff to prefer an appeal before the Eight Circuit on the ground that the District Court had abused its discretion.

In reviewing the decision of the District Court, the Eight Circuit reiterated the tenets of Fed. R. Evid. 702. and the holdings of the Supreme Court in Daubert where it had mandated the District Courts to focus on principles and methodology of the expert testimony rather than the conclusions that they generate.

The Appellate Court did not find the trial Court guilty of abusing its discretion in excluding the Plaintiff’s expert’s ultimate opinion since neither could the expert gauge the time when the corrosion pits formed, nor could he trace the fatigue cracks that caused the axle failures. During discovery the expert had also acknowledged that “corrosion rates are inherently difficult to predict.” In light of this evidence, the District Court had rightfully concluded that a gap existed between the data and the expert’s ultimate opinion.  (Joiner, 522 U.S. at 146)

The Plaintiff’s argument that its expert rejection of other probable causes for the axle failures was a reliable methodology for his opinion also failed as the Eight Circuit found the expert incapable of distinguishing between the corrosion pits that the Defendant allegedly failed to remove and those that formed after the axles left their facility. The Eight Circuit therefore held that the District Court had exercised its gate keeping function in excluding the ultimate opinion of the Plaintiff’s expert as unreliable (Daubert 509 U.S. at 589)

The Plaintiff’s second contention was that the District Court had abused its discretion in admitting the Defendant’s expert testimony although (i) his opinions were unrelated to the facts of this case, (ii) he had not taken into account pertinent facts and (iii) had examined and considered one piece of evidence—the axle.

 The Defendant’s expert had opined that in the absence of corrosion pitting at the initiation sites, the derailments could not be attributed to their presence. He had further testified that fretting caused the accumulation of stress which in turn allowed a fatigue crack to initiate and grow. Thus, although the Defendant’s expert was unable to associate the cause of the fatigue cracks to corrosion pitting, he was successful in identifying fretting as the cause behind the crack in the axle.

The judgment of the District Court was thereby affirmed.