Don’t Undermine Daubert: Second Circuit Should Affirm Trial Court's Exclusion of Unreliable Expert Testimony

Why It Matters

Upholding Cote’s ruling preserves the Daubert gatekeeping standard, protecting courts from speculative, scientifically unsound claims that could flood litigation and distort product liability outcomes.

Key Takeaways

• Daubert requires judges to gatekeep expert testimony
• Judge Cote excluded experts for cherry‑picking data
• Genetic confounding accounts for ~80% ASD, 74% ADHD
• 2nd Circuit must apply “abuse of discretion” standard
• Overturning would invite junk science lawsuits

Pulse Analysis

The Daubert trilogy—Daubert, Joiner, and Kumho—forms the cornerstone of U.S. courts' ability to filter expert testimony under Federal Rule of Evidence 702. By demanding methodological reliability and relevance, the doctrine empowers trial judges to act as gatekeepers, preventing unvalidated scientific claims from reaching juries. This framework has become essential in complex product liability disputes where the line between emerging research and established science can be thin, and its consistent application safeguards the integrity of the evidentiary process.

In the Acetaminophen‑ASD/ADHD litigation, Judge Cote applied Daubert rigorously. She found that Dr. Ness and Dr. Baccarelli selectively cited studies, ignored the dominant genetic contribution—estimated at 80% for autism and 74% for ADHD—and lacked the expertise to answer basic questions about ADHD. Moreover, the defendant’s expert, Dr. Faraone, never asserted a causal link, and his statements were taken out of context. By excluding these opinions, the district court adhered to the principle that each analytical step must be reliable; a single flawed step renders the entire testimony inadmissible.

The appellate review is limited to an "abuse of discretion" inquiry, meaning the 2nd Circuit can overturn only manifest errors. Upholding Cote’s decision reinforces a 30‑year jurisprudential line that shields courts from a surge of pseudo‑scientific claims. If reversed, plaintiffs could weaponize tenuous epidemiological associations to revive dormant product liability suits, increasing litigation costs and eroding public confidence in scientific evidence. Maintaining the Daubert gatekeeping function thus remains vital for both legal predictability and the broader credibility of expert testimony in the marketplace.