Search for Attorney CPA


By James D. Gassenheimer and Ashley Dillman Bruce 

As trial lawyers, we are confronted by expert witnesses in every aspect of our work.  They testify as to damages such as lost profits, product defects, duties and standards of care, causes of personal injuries, intellectual property, and in other areas.  But before admitting an expert’s testimony, the Supreme Court has explained that the trial court serves a gatekeeping function, “ensuring that an expert’s testimony both rests on a reliable foundation and is relevant to the task at hand.”  Gatekeeping requires the trial court to make “a preliminary assessment of whether the reasoning or methodology underlying the testimony is valid and of whether that reasoning or methodology properly can be applied to the facts in issue.” In recent years, the trial court’s gatekeeping function of whether to admit into evidence an expert’s testimony, has morphed in an ever-increasing rigorous inquiry resulting in a frequent striking of testimony.  While a majority of federal appellate courts afford more deference to the fact finder in evaluating the strength of expert testimony, recognizing that trial courts appropriately fulfill their role as gatekeepers when they allow expert testimony to be attacked through the adversarial process of trial, the Eleventh Circuit is not among them.  This minority follows a heightened standard of admissibility, that excludes expert testimony when the expert fails to test possible alternative conclusions or when the expert’s conclusions were the result of a flawed execution of the expert’s methodology. 

In 2010, the Eleventh Circuit reinforced its position in the minority when it affirmed a trial court’s exclusion of expert testimony in Kilpatrick v. Berg Inc., 613 F.3d 1329 (11th Cir. 2010).  As explained in a previous article,  this searching and aggressive inquiry may have gone too far in greatly broadening the scope of the court’s power to act as gatekeeper.  Nonetheless, in the years since Kilpatrick, the Eleventh Circuit has not relented. 

The year following Kilpatrick, the Eleventh Circuit again affirmed a trial court’s exclusion of an expert testimony, this time, in a products liability action against a manufacturer of hip prosthesis because the metallurgist’s expert’s “methodology was unreliable.”  The court reasoned that the expert’s theory was “virtually incapable of being tested,” and found that the expert could not state with certainty how metal particles became dislodged from the hip prosthesis because of chemical irregularity on its surface.  The court noted that the expert’s theory was not subjected to peer review and explained that the expert “was unable . . . to identify any publications or scientific studies that supported” his theory.  Accordingly, after a searching review, the Eleventh Circuit affirmed the trial court’s decision to exclude the expert’s testimony.

Two years later, the Eleventh Circuit was again tasked with considering a trial court’s review of expert testimony.  There, motorists brought an action against a truck driver and the driver’s employer for injuries from an accident.  The trial court endorsed the “one-two punch” in excluding the motorists’ expert report and then granting summary judgment for the driver and employer.  On appeal, the Eleventh Circuit affirmed, finding that although the expert had “extensive experience in his field,” the expert’s opinion “was not the product of a scientifically reliable methodology” since that expert created his opinion by learning and thinking about the case and reaching a conclusion.  He did not conduct any testing, and his “methodology was not reliable because it was not derived from the scientific method; rather, it amounted to asking the district court simply to take the expert’s word for it.”

Finally, in 2016, the Eleventh Circuit affirmed the trial court’s exclusion based on the expert’s methodology being speculative and unreliable. There, the expert cardiologist’s opinion testimony hinged on the existence of a measurable time gap between the effects of a medicine.  But after an in-depth review of the expert’s testimony, the Eleventh Circuit concluded that:  “Simply put, [the expert] presented only speculative evidence regarding the first number in his attempt at a time-gap measurement” and “while an opinion based on extrapolation is allowed, there must be some basis for that extrapolation.” 

This trilogy of cases  confirms that the analysis employed by the Eleventh Circuit since Kilpatrick to vest in our trial courts tremendous discretion.  These decisions make clear that the Eleventh Circuit’s stance on the admissibility of expert opinions continues to require careful planning and preparation.   When, if ever, will the reigns be let out is anyone’s guess.

James D. Gassenheimer, a partner on the Dispute Resolution Team at Berger Singerman, has extensive jury and non-jury trial experience in State, Federal and Bankruptcy Court, having tried over 100 cases to jury verdict or judgment. Ashley Dillman Bruce is Of Counsel on the Business Reorganization Team at Berger Singerman. She concentrates her practice on corporate bankruptcy, insolvency representations, and a variety of complex commercial litigation matters. They can be reached at and

  1 Gassenheimer, James G., The Federal Lawyer pg. 74 (June 2013), available at


© 2023 . All rights reserved.