News Release

May 27, 2025

 

Full Federal Circuit Upholds Trial Judges' Expert Testimony Gatekeeping Role In Patent Infringement Cases

As part of its top-ranked Amicus Program, ALF long has been one of the nation’s foremost advocates for ensuring that federal district courts fulfill their expert testimony gatekeeping role under Federal Rule of Evidence 702 by admitting into evidence only expert testimony that is reliable. Our amicus brief in EcoFactor, Inc. v. Google LLC, a patent infringement appeal, urged the en banc Federal Circuit to enforce the expert testimony reliability criteria established by Rule 702, as amended in December 2023. The Federal Circuit's May 21, 2025 en banc majority opinion does exactly that.


Google, having been held liable for infringing a patent relating to operation of computer-networked smart thermostats, challenged a Texas district court judge's admission of the plaintiff's expert testimony on damages. A panel of the Federal Circuit (which has exclusive jurisdiction over patent infringement appeals) affirmed, but the court of appeals then granted Google's petition for rehearing en banc and ruled that Google is entitled to a new trial on damages.


Like ALF's amicus brief, the court's en banc opinion traces Rule 702's evolution back to Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), where the Supreme Court explained the trial judge plays a “gatekeeping role,” id. at 597, through which it must “ensure that any and all scientific testimony or evidence admitted is not only relevant, but reliable,” id. at 589. Rule 702 was amended in 2023, however, due to widespread misapplication by trial judges, who were shirking their gatekeeping role by ruling that the reliability of an expert's testimony are questions of weight and credibility for a jury to decide. As a result, the 2023 amendments, and the accompnaying advisory committee notes, clarify and strengthen federal trial judges' expert testimony gatekeeping role.


The Federal Circuit's much-anticipated en banc opinion explains why "[d]eterminations of admissibility, which fall within the gatekeeping role of the court, are separate from determinations of weight and credibility, which are within the province of the jury in a jury case." The court of appeals indicated that "[d]istinguishing the gatekeeping role of the judge under Rule 702 from the fact finder’s role is particularly essential in the context of patent damages.”


ALF's amicus brief was authored by Eric G. Lasker and Katherine E. Nolan of Hollingsworth LLP and ALF Executive Vice President & General Counsel, Lawrence S. Ebner.

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Media Contact: Larry Ebner
lawrence.ebner@atlanticlegal.org | Tel: 202-872-0011
 

About the Atlantic Legal Foundation


For almost half a century, the Atlantic Legal Foundation, a national, nonprofit, nonpartisan, public interest law firm, has advocated in the Supreme Court, federal courts of appeals, and state appellate courts for individual liberty, free enterprise, property rights, limited & responsible government, sound science in judicial & regulatory proceedings, and effective education, including parental rights and school choice.

 

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