Background
In 2015, American Airlines contracted with Twin Hill Acquisition to manufacture uniforms for flight attendants and other employees. When the uniforms were rolled out in 2016, hundreds of employees reported health complaints ranging from itching and scratchy eyes to allergic reactions, rashes, hives, and respiratory symptoms. Some even claimed “proximity reactions”—severe allergic reactions from merely being near people wearing the uniforms. American conducted pre- and post-release chemical testing through Intertek and the National Institute for Occupational Safety and Health (NIOSH). These tests detected low levels of chemicals that theoretically could trigger allergic reactions, but all expert testing concluded the quantities were too low to cause the reported symptoms, and proximity reactions were highly unlikely.
After one month, American discontinued the Twin Hill uniforms and eventually replaced them with alternatives from Lands’ End by 2020. In August 2017, a group of 74 named employees sued Twin Hill and American Airlines under the Class Action Fairness Act, asserting strict and negligent products liability claims, as well as battery and intentional infliction of emotional distress. The plaintiffs initially sought class certification but later dropped that claim in their third amended complaint, citing passage of time. They subsequently restored class allegations in a fourth amended complaint to preserve federal jurisdiction.
The defendants moved for summary judgment in September 2024, seeking to exclude the testimony of the plaintiffs’ two expert witnesses, Dr. Arch Carson and Dr. Peter Hauser, on grounds of unreliable methodology. The district court granted summary judgment for the defendants, excluding the expert testimony and holding that without it, the plaintiffs could not establish any defect or causation. The plaintiffs appealed, invoking the tort doctrines of res ipsa loquitur and the “Tweedy doctrine” to overcome the evidentiary gap.
The Court’s Holding
The Seventh Circuit first addressed subject matter jurisdiction under CAFA, which requires that the action be “filed under” Federal Rule 23 (class action rule). After the Supreme Court’s decision in Royal Canin, which held that amended complaints effectively remake a suit and its jurisdictional basis, the court analyzed whether plaintiffs’ abandonment of class claims in the third amended complaint destroyed jurisdiction. The court concluded that it did not, because the operative fourth amended complaint, filed in response to the district court’s request for supplemental briefing, unambiguously invoked CAFA and pleaded all jurisdictional prerequisites. Under Royal Canin’s logic, each amended complaint is evaluated independently, so the fourth amended complaint effectively re-filed the case as a class action and secured jurisdiction, even though an intervening amendment had created jurisdictional uncertainty.
On the merits, the court affirmed the exclusion of the plaintiffs’ experts. Under revised Federal Rule of Evidence 702, expert testimony must employ reliable methodology. Dr. Carson and Dr. Hauser used unreliable methods to conclude the uniforms caused injuries, and notably, even these experts conceded that no identifiable chemical or group of chemicals in the uniforms could trigger the range of reactions plaintiffs alleged. Without expert testimony on causation and defect, plaintiffs had no evidence to present to a jury—particularly no basis for “proximity reactions” occurring from mere proximity to the uniforms.
The court then rejected plaintiffs’ invocation of res ipsa loquitur and the Tweedy doctrine. Under Illinois law, the Tweedy doctrine allows a strict liability claim to proceed without proof of a specific defect if the product “failed to perform as reasonably expected” and no other reasonable causes exist. However, the court held Tweedy inapplicable because these uniforms did not “fail” in the traditional sense—they did not break, collapse, or malfunction. Moreover, the court found numerous alternative explanations for plaintiffs’ varied symptoms (different underlying medical conditions, placement of complaints) that undermined any inference that a single product defect was responsible. Traditional res ipsa loquitur for negligence also failed because plaintiffs could not establish that injuries of this type ordinarily do not occur without negligence, and Twin Hill had long since lost exclusive control over the uniforms after they were manufactured, shipped, washed, and worn.
Key Takeaways
- CAFA jurisdiction is determined by the operative amended complaint at the time of decision, not the original complaint; plaintiffs can destroy jurisdiction through amendment but may restore it through a subsequent amended complaint that properly pleads CAFA’s prerequisites.
- Expert testimony in products liability cases must employ reliable methodology; without reliable expert testimony, plaintiffs cannot satisfy their burden to prove defect and causation, even if circumstantial evidence is suggestive.
- The Tweedy doctrine applies only to traditional product “failures” (brake failure, device malfunction, structural collapse) and does not extend to diffuse health complaints arising from non-obvious chemical exposure when alternative explanations exist.
- Res ipsa loquitur cannot overcome absent expert evidence in complex causation cases; the fact that injuries occurred does not “speak for itself” when multiple alternative explanations are plausible.
Why It Matters
This decision clarifies CAFA jurisdiction in the post-Royal Canin landscape. Parties can now amend complaints strategically to add or remove class allegations, but the operative complaint at the time of the district court’s ruling controls jurisdiction. This creates both opportunity and risk for plaintiffs: abandoning class claims may preserve party diversity or lower the amount-in-controversy threshold, but it can trigger jurisdictional uncertainty that must be cured by subsequent amendment. The decision confirms that Seventh Circuit precedent in In re Burlington, which preserved CAFA jurisdiction despite dropped class allegations, may now be on thin ice after Royal Canin, leaving future removal-jurisdiction CAFA cases in flux.
The opinion also reinforces stringent evidentiary requirements in products liability litigation. In an era of mass health complaints and environmental torts, plaintiffs cannot rely solely on circumstantial evidence, res ipsa loquitur, or doctrines designed for obvious product failures to bypass the need for reliable expert testimony showing defect and causation. The court’s rejection of Tweedy and res ipsa loquitur signals that diffuse, multi-symptom health complaints require particularized proof, not inference from the fact that many people got sick. This sets a meaningful barrier for plaintiffs in occupational health and mass-exposure cases where causation is complex and alternative explanations abound.