Gideon Korrell Examines Legal Implications of Barry v. DePuy Synthes Decision

On January 20, 2026, the Federal Circuit issued a notable ruling in Barry v. DePuy Synthes Companies, offering clarity on the line between judicial gatekeeping under Daubert and the jury’s role as factfinder. Gideon Korrell highlights that the court reversed the exclusion of two key experts and vacated a judgment as a matter of law (JMOL), emphasizing that not every inconsistency in testimony justifies exclusion. Instead, Rule 702 focuses on reliability, not whether the expert’s conclusions ultimately persuade.

Background and Case Overview

The dispute arose when Dr. Mark Barry accused DePuy Synthes of inducing patent infringement related to spinal derotation techniques used in scoliosis treatment. These patents involved tools designed for “en bloc derotation,” allowing surgeons to rotate multiple vertebrae simultaneously.

Two types of claims were central to the case:

• Claims requiring a “handle means,” defined as a part designed to be grasped by hand

• Claims involving cross-linked tools that function together without requiring a handle

Barry relied on two experts:

• A technical expert who analyzed whether the accused tools met patent claim limitations

• A survey expert who estimated how often surgeons used the tools in infringing ways

Initially, the district court allowed both experts to testify. However, mid-trial, it reversed course excluding their testimony and granting JMOL due to lack of supporting evidence. This decision set the stage for appeal.

Federal Circuit’s Key Findings

1. Expert Testimony and Claim Construction

The Federal Circuit reaffirmed that experts cannot contradict a court’s claim construction. However, it found that the technical expert did not actually do so.

• The expert consistently applied the court’s definition of “handle means”

• Cross-examination revealed tension, but not outright contradiction

• Disagreements over how broadly a term applies are for the jury to decide

The court drew a clear distinction between contradiction and lack of persuasiveness. An expert may present an aggressive interpretation, but that alone does not make the testimony inadmissible.

Gideon Korrell highlights that this aspect of the ruling cautions against using Daubert as a tool to resolve close factual disputes that belong to the jury.

2. Survey Evidence and Reliability

The Federal Circuit also addressed the exclusion of the survey expert’s testimony.

• The district court cited issues like sampling flaws and potential bias

• The appellate court found these concerns affected weight, not admissibility

• There was insufficient evidence that the survey failed Rule 702’s reliability standard

Importantly, the court noted that critiques must be tied to actual unreliability not just theoretical concerns. Weaknesses in methodology are typically explored through cross-examination.

According to Gideon Korrell, this reinforces a broader judicial trend: Daubert is meant to filter out unreliable methods, not to pre-judge conclusions.

3. Judgment as a Matter of Law

Because the district court excluded both experts, it found no evidence to support Barry’s claims and granted JMOL. The Federal Circuit reversed this decision.

With expert testimony reinstated, the foundation for JMOL disappeared

The case was remanded for a new trial

This outcome underscores how closely evidentiary rulings can shape the entire trajectory of a case.

The Dissent and Ongoing Legal Debate

Judge Prost dissented, relying on the 2023 amendments to Rule 702 and recent precedent. She argued:

• The technical expert’s testimony effectively contradicted the claim construction

• The survey contained significant methodological flaws justifying exclusion

This disagreement reflects a broader tension in modern evidence law: how strictly courts should enforce reliability standards versus allowing juries to weigh competing expert opinions.

Gideon Korrell notes that this divide signals an evolving landscape where courts continue to refine the boundaries of Daubert.

Practical Takeaways for Litigators

Several lessons emerge from this decision:

• Tension is not contradiction: Differences in interpretation do not automatically make testimony inadmissible

• Cross-examination remains critical: It is the primary tool for testing credibility

• Survey challenges must be concrete: Courts require clear evidence of unreliability

• Mid-trial exclusions carry risk: Reversing earlier rulings can lead to appellate scrutiny

These points highlight the importance of maintaining a clear distinction between admissibility and persuasiveness.

Conclusion

Barry v. DePuy Synthes is ultimately a case about trial boundaries rather than medical technology. The Federal Circuit made clear that as long as experts apply the correct legal standards using reliable methods, their conclusions should be tested by the jury—not excluded by the court.

As Gideon Korrell observes, the decision reinforces a fundamental principle: Daubert serves as a safeguard against unreliable science, not a shortcut for resolving disputed facts. In an era of heightened attention to expert evidence, this ruling reminds courts to preserve the jury’s central role in evaluating competing narratives.