The Federal Circuit’s recent decisions in EcoFactor, Inc. v. Google, LLC (en banc) and Barry v. DePuy Synthes Companies have refined the landscape regarding the admissibility of expert testimony under Federal Rule of Evidence 702 and Daubert. These rulings highlight an escalating tension concerning the "gatekeeping" role of district judges versus the "factfinding" role of juries.
The EcoFactor shift: From flexibility to strict gatekeeping
The story of EcoFactor, Inc. v. Google LLC began with a June 2024 panel decision where a majority affirmed a $20 million damages award against Google. The panel majority held that disputes over an expert's derivation of a royalty rate from lump-sum licenses were "factual issues best addressed by cross examination and not by exclusion." Judge Prost, however, issued a sharp dissent-in-part, arguing that the expert had "conjured" a royalty rate from "self-serving, unilateral 'recitals'" in license agreements that were contradicted by the contracts' operative terms.
On May 21, 2025, the Federal Circuit, sitting en banc, adopted Judge Prost’s position. The full court reversed the damages award, holding that the district court abused its discretion by admitting the expert's testimony. The en banc majority emphasized that a district court must ensure that an expert’s conclusions do not "go beyond what the expert’s basis and methodology may reliably support." The court found that the damages expert’s assertion that prior willing licensees had agreed to a certain royalty rate was not supported by the plain language of the licenses, especially when two of the licensees had expressly disclaimed those rates in the body of the contracts. Because of this, the court held that the district court failed to fulfill its responsibility as gatekeeper by allowing the expert’s testimony where the fundamental premise of his opinion was contrary to the relevant evidence and thus not based on sufficient facts or data as required by Rule 702(b).
Barry v. DePuy: A counter-current in the Daubert tide
Contrasting this rigorous gatekeeping is the January 20, 2026, decision in Barry v. DePuy Synthes. In Barry, after denying the defendant’s pretrial Daubert motions, the district court excluded two of the plaintiff’s experts during trial, finding that the technical expert had contradicted the court's claim construction and that the survey expert’s methodology was "riddled with methodological flaws." The Federal Circuit panel, however, reversed and found that the district court judge abused his discretion in excluding the plaintiff’s experts.
The Barry majority held that the district court's finding of the technical expert’s "contradiction" with the district court’s claim construction was clearly erroneous; instead, the expert had offered an "application" of the construction that was a matter for the jury to weigh. The Federal Circuit warned that treating "arguable inconsistencies" as a basis for exclusion would "broadly undermine fair and orderly pretrial preparation" and "inadvertently invite district courts to dismantle parties’ cases at trial based on ordinary evidentiary imperfections.” The Barry majority further held that “the district court’s non-record-based reasoning as to methodological flaws does not, on its own, justify exclusion of [the survey expert’s] opinion.” Rather, the majority acknowledged that the “district court recognized that ‘a survey’s methodological deficiencies generally go to its evidentiary weight rather than to its admissibility’” and found “no persuasive reasons for finding this case to be an exception.”
The common thread: Judge Prost’s dissenting voice
The tension between these cases is embodied in the dissenting opinions of Judge Prost, who dissented in both Barry and the Federal Circuit’s 2024 EcoFactor panel decision (the panel decision was later vacated when the court granted rehearing en banc). In both dissents, Judge Prost criticized an overbroad tendency to characterize reliability defects as matters for cross-examination.
In EcoFactor (panel), Judge Prost dissented and exclaimed that the damages expert’s opinion rested on unsupported assumptions and treating those defects as issues of “weight” improperly abdicated the district court’s Rule 702 gatekeeping role.
In Barry, Judge Prost made the same point in a different setting: When testimony is inconsistent with claim construction or rests on flawed survey design, Rule 702 assigns the reliability decision to the court. Judge Prost argued that the Barry majority was contravening the very principles the court had just reasserted en banc in EcoFactor and criticized the "everything’s a fact or weight issue" approach as a failure to satisfy the 2023 amendments to Rule 702.
Predictions for En Banc Review in Barry
The tension between EcoFactor (en banc) and Barry (panel) creates a prime candidate for further en banc review. Given the 2023 amendments to Rule 702 — which emphasize that the proponent must demonstrate reliability to the court— the full Federal Circuit may feel compelled to clarify whether Barry’s "adversarial testing" standard is at odds with the "gatekeeping" mandate of EcoFactor. If taken en banc, the court is likely to harmonize Barry with the EcoFactor requirement that an expert’s factual premises must be supported by more than just the expert’s conclusory statements.
Takeaways
- Anchor Daubert challenges in legal, not merely scientific, failures. The most effective challenges are those showing that an expert ignored controlling legal constraints — such as express contract language or a failure to apportion damages — rather than merely disputing whether the expert followed specific scientific methodologies.
- Distinguish methodological unreliability from disputed conclusions. Post-Barry, courts may be reluctant to exclude experts where the dispute centers on how the expert applied an accepted methodology.
- Attempt to build a Rule 702 record. EcoFactor makes clear that unexplained admissibility rulings are vulnerable on appeal. Parties should press district courts to articulate their gatekeeping analysis.
