This morning, the Federal Circuit released a precedential opinion in a patent case appealed from the Eastern District of Pennsylvania. The Federal Circuit concluded that the district court both abused its discretion in excluding expert testimony and erred in granting judgment as a matter of law. Notably, Judge Prost filed a dissenting opinion. Here are the introductions to the opinions.
Barry v. Depuy Synthes Cos. (Precedential)
Dr. Mark A. Barry sued DePuy Synthes Sales, Inc., Medical Device Business Services, Inc., and DePuy Synthes Products, Inc. (together, “DePuy”) in the United States District Court for the Eastern District of Pennsylvania, alleging that DePuy induced surgeons to infringe certain claims of Barry’s U.S. Patent Nos. 7,670,358 (the “’358 patent”), 8,361,121 (the “’121 patent”), and 9,668,787 (the “’787 patent”) (collectively, “the Asserted Patents”). At trial, DePuy moved to exclude two of Barry’s experts, Dr. Walid Yassir and Dr. David Neal, and the district court granted these motions. It further granted judgment as a matter of law (“JMOL”) to DePuy.
Barry now appeals. We conclude that the district court abused its discretion in excluding the expert testimony and erred in granting JMOL. We therefore reverse the judgment for DePuy and remand for a new trial at which both Drs. Yassir and Neal may testify.
Judge Prost, dissenting.
The district court properly excluded Barry’s expert testimony because it was unreliable. Dr. Yassir, Barry’s technical expert, contradicted the court’s claim construction. And Dr. Neal’s testimony regarding his survey was riddled with methodological flaws, specifically concerning the representativeness of his sample and the design of his questions.
The majority reverses the district court’s ample discretion on these issues; it announces that all of these contradictions and flaws were matters of fact or weight, properly left to the jury to sort out. I disagree. We just recently convened en banc to reassert the “essential prerequisite” of a court’s reliability determination for expert testimony to be considered by a jury. See EcoFactor, Inc. v. Google LLC, 137 F.4th 1333, 1340 (Fed. Cir. 2025) (en banc). As the 2023 amendments to the Federal Rules of Evidence now make abundantly clear, the proponent of evidence must “demonstrate[] to the court” its reliability. Fed. R. Evid. 702 (emphasis added). The Advisory Committee explicitly criticized district courts for treating the “critical questions of the sufficiency of an expert’s basis, and the application of the expert’s methodology” as “questions of weight and not admissibility.” Fed. R. Evid. 702 advisory committee’s note to 2023 amendments. The majority’s approach— where everything’s a fact or weight issue for the jury—contravenes the principles embraced in EcoFactor and the 2023 amendments, and in my view will undermine district courts’ abilities to exercise their important gatekeeping function. I respectfully dissent.