Every good mystery needs a red herring. The suspicious houseguest. The gardener with the shaky alibi. The tanning lotion sitting quietly on the bathroom counter while the actual culprit — a chiropractor-prescribed anti-inflammatory cream applied minutes before the plaintiff’s collapse — walks right past the detectives without so much as a raised eyebrow. That is essentially the plot of today’s case, and unlike most mystery novels, the court had no trouble figuring out who did it.

The case is Mattox v. Product Innovations Research, LLC, 2026 WL 2071209 (E.D. Okla. Jul. 17, 2026). Plaintiff alleged she suffered a severe allergic reaction after using defendant’s tanning lotion (not sunscreen; no active SPF ingredients). Id. at *1-2. The complaint asserted claims for ordinary negligence, negligent training, negligent supervision, and strict products liability. But all four counts overlapped and boiled down to an allegation that defendant failed to sufficiently disclose an allergen plaintiffs believed was lurking in the formula. Id. at *4. Before we even get to causation, the court had to clear away a pile of duty theories that plaintiffs tried to stack on top of ordinary failure-to-warn law.

Plaintiffs argued that Oklahoma law imposes a broad, generalized duty on manufacturers “to avoid foreseeable harm” caused by mislabeling, failure to warn, failure to test, failure to adhere to industry standards, failure to comply with federal regulations, and negligent formulation. Id. at *5. That is a lot of duty to hang on the five cases plaintiffs cite, and the court was not having it. Going case by case, the court held that alleged deficiencies in labeling, testing, or formulation are “factual theories by which a plaintiff may attempt to show breach of [the] warnings-and-instructions duty; they are not independent duties” in their own right. Id. The court was similarly unimpressed by the argument that Oklahoma recognizes a separate duty to avoid misleading consumers. The court held that the case plaintiffs relied on presupposes existing strict-liability duties regarding design and warnings and does not recognize a separate negligence duty to avoid misleading consumers. Id. If plaintiffs want to complain about misleading labeling, that is a warning claim, full stop.

Next, plaintiffs cited a case to suggest that failure to comply with FDCA regulations can be a basis for a negligence per se claim. But plaintiffs did not bring such a claim.  Therefore, “plaintiffs’ references to federal regulations are properly treated, at most, as evidence bearing on ordinary negligence, not as an independent cause of action.” Id. at *14, n.5. Finally, as far as adhering to industry standards is concerned, Oklahoma law (a) provides that it can serve “as non-dispositive evidence bearing on breach of duties otherwise established” and (b) “limits the defensive use of industry-custom evidence” under the state’s strict-liability framework. Neither case cited by plaintiffs equates failure to adhere to industry standards as the broad breach of duty urged by plaintiffs. Id. at *6.

Plaintiffs also reached for res ipsa loquitur, arguing that a catastrophic allergic reaction just does not happen absent negligence. Id. The court’s response amounts to a well-deserved eye roll. “Res ipsa loquitur does not create a new duty, does not supply a product defect, and does not apply where the injury may reasonably occur in the absence of negligence.” Id. Allergic reactions, as any first-year torts student (or allergy sufferer) knows, are the textbook example of harm that can occur even when everyone did everything right. That is rather the point of an allergy — it is idiosyncratic to the person, not necessarily indicative of some derelict manufacturing process.

Next up was a spoliation argument. We will not dwell here, but it is worth a passing mention because it quietly foreshadows the causation problem to come. Defendants argued that plaintiffs’ failure to retain the actual bottle of lotion — a nonparty clinic employee tossed it before litigation even started — should sink the case on product identification and spoliation grounds. Id. at *8. The court declined to go that far, finding no evidence of a duty to preserve or culpable conduct sufficient to support sanctions, and holding that circumstantial evidence (photos, testimony, packaging) could get plaintiffs to a jury on product identification. Id. at *8-9. No spoliation defense here. But without the bottle, nobody could ever test what was actually in it. That gap in the record was consequential on causation.

Even assuming plaintiffs could get past duty and defect, they still needed evidence that the lotion — as opposed to literally anything else — caused the reaction. And their own evidence torpedoed them. Start with the timeline. The undisputed chronology showed days of uneventful use of defendant’s lotion, followed by a sudden, severe reaction that started right after application of a chiropractor-prescribed anti-inflammatory cream. Id. at *10. The history obtained by emergency personnel reflected that plaintiff began vomiting and experiencing shortness of breath after her husband applied the anti-inflammatory cream to her chest and back, and that she had a severe allergy to certain types of nuts and to ibuprofen. Id.

Plaintiffs relied on an allergist’s opinion that certain ingredients in the tanning lotion “may have contained” almond oil and that therefore, the lotion “likely” caused the reaction. Id. But plaintiffs’ expert’s own testing worked against them. Although plaintiff tested positive to almond on a tree nut skin-test panel, she tested negative when skin-tested with defendant’s tanning lotion itself. Id. That is about as clean a rebuttal as a defendant could ask for — the plaintiff is allergic to almonds, sure, but when you test her against the actual product she is suing over, nothing happens.

The court did not mince words about what this evidence amounted to. The court held that the expert’s causation opinion rested primarily on temporal association and the general allergenic potential of certain ingredient classes, rather than on testing that confirmed the presence and concentration of a particular allergen in the product as sold and applied. Id. at *11. Plaintiffs never established that a specific allergenic ingredient was actually present in the product they sued over. Remember, plaintiff tested negative for any allergic reaction to the tanning lotion generally and plaintiffs could not test the particular bottle she used because it was thrown away.  We told you the spoliation argument was foreshadowing. All plaintiffs had was a mere possibility that the product could have caused the injury. That is insufficient to establish defect or causation under Oklahoma law. Id.

Further, temporal association alone does not equal causation — particularly when there is a far more obvious, far better-timed alternative cause sitting right there in the medical chart. And in a footnote that is basically the judicial equivalent of a mic drop, the court noted that plaintiffs’ expert’s report did not address plaintiff’s intervening application of an anti-inflammatory cream, which undermined the temporal association on which his opinion relied. Id. at *14 n.9.

While plaintiffs tried to point to a lack of product testing, they identified no authority, state or federal, “imposing a duty on [the manufacturer] to conduct allergen testing or maintain post-market surveillance.” Id. at *10.  Combined with a causation case built entirely on speculation and bad timing, testing omissions, if any, do not themselves constitute a design or manufacturing defect. Id. The court held that plaintiffs had not identified a specific design or manufacturing defect that rendered defendant’s product unreasonably dangerous to ordinary consumers, and that the timing and circumstances of the reaction more closely aligned with the application of a different product, entitling defendants to judgment as a matter of law. Id. at *11.

With no viable underlying tort, punitive damages were dead on arrival — you cannot get exemplary damages on a claim that does not exist. Id. at *12. But the court went further and made a point worth bookmarking for future cases — alleged regulatory violations or deviation from industry-standard practices, without more, do not constitute clear and convincing evidence of reckless disregard or malice sufficient to support punitive damages under Oklahoma law. Id. Plaintiffs cannot dress up ordinary testing and labeling disagreements as the kind of conscious disregard that gets a jury an exemplary-damages instruction.

The court also did not need to reach plaintiff’s motion for summary judgment on defendant’s affirmative defenses of assumption of the risk and intervening cause, but it is a nice bit of belt-and-suspenders reasoning for the defense side of the ledger. The court found that the undisputed record — including plaintiff’s awareness of her severe nut and ibuprofen allergies, her repeated uneventful use of the lotion before the incident, and the onset of symptoms immediately after application of the anti-inflammatory cream — precluded the court from holding as a matter of law that no reasonable jury could find some degree of voluntary exposure to known risks or an independent, intervening cause Id. at *12-13.

Too many plaintiffs try to get from “I used a product and later got sick” to “the product made me sick” using nothing but sequence and suspicion. Post hoc ergo propter hoc is a logical fallacy, not a causation standard, and this court called it out for exactly that. When the plaintiff’s own medical history places the trigger event immediately after exposure to a different product, and the plaintiff’s own expert’s own testing comes back negative against the accused product, there is no jury question left to manufacture. The tanning lotion was the obvious suspect — sitting right there in the story, easy to blame, easy to sue. But the real cause of the reaction was somewhere else entirely, and the court, unlike plaintiffs’ counsel, actually followed the evidence to where it led. Case closed.