The U.S. Court of Appeals for the Federal Circuit issued an en banc opinion in EcoFactor, Inc. v. Google LLC, 137 F.4th 1333 (2025) emphasizing the court’s responsibility in gatekeeping the admissibility of expert testimony. The Federal Circuit reversed the District Court’s decision to admit a damages expert and granted a new trial. The court underscored the district court’s function and responsibility under Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993) to ensure expert testimony is reliable and based on a sufficient factual foundation.
As of March 2026, EcoFactor, Inc., the decision was cited in 25 times in judicial opinions: 5 citations from the U.S. Court of Appeals for the Federal Circuit, 17 citations from federal district courts, and one citation from the Ohio Court of Appeals. This decision can have far-reaching implications in patent litigation and beyond, as it may lead to district courts applying higher levels of scrutiny in relation to determining the reliability and admissibility of expert opinions and testimony. While the true impact remains to be seen, one thing is certain: this en banc decision has captured the attention of a large audience.
Of note, in Willis Elec. Co., Ltd. v. Plygroup Ltd., the Federal Circuit distinguished EcoFactor, arguing that Mr. Kennedy’s expert testimony was unreliable “because it was predicated on an inaccurate characterization of the licenses.” 166 F.4 1363 (2026). In consideration of Willis, it is foreseeable that determinations referencing EcoFactor and its progeny will be made on a case-by-case basis, diving deeper into whether expert opinion or testimony is sufficiently supported by facts and data.
