Today’s post is not from the Butler Snow side of the blog.
It’s five days post-Thanksgiving and if you are like the majority of us, there are still leftovers in your fridge. But according to food safety experts, yesterday was likely the last day for the turkey, mashed potatoes, stuffing, gravy, and casseroles. Some legal theories are like those leftovers–they may have started out fine, but after enough time passes, you’re really just gambling with your health. Extending a post-sale duty to warn to a successor company that didn’t manufacture or sell a medical device when it was implanted is one such culinary adventure. It’s a doctrine that, if expanded any further, might as well come with its own hazard label: Warning: May cause logical indigestion.
And it’s an issue that the court in the In re Paraguard IUD Products Liability Litigation is grappling with. The product was originally manufactured and sold by Teva. But in November 2017, the NDA was purchased by Coopersurgical. Coopersurgical moved for summary judgement in cases where plaintiffs’ IUDs were implanted prior to 2017, so manufactured and sold by Teva, but explanted after the change of ownership—at which time it was discovered the IUDs had broken.
Plaintiffs did not even bother to respond to the motion on design defect. There is simply no way Coopersurgical could have made any changes to the design of the device at any time material to these plaintiffs’ claims. In re Paraguard IUD Products Liability Litigation, 1:20-md-02974-LLM, slip op., at 4 (N.D. Ga. Nov. 21, 2025).
On failure to warn, plaintiffs urged the court to adopt the Restatement 3d of Torts: Products Liability, §13(a), which creates a post-sale duty to warn for successor companies who have a “similar relationship with purchasers of the predecessor’s products.” Id. at 5. However, Florida law applies to the cases at issue and Florida has not adopted §13. Therefore, defendant argued it would be an improper expansion of Florida law for the court to apply it here. During oral argument it became clear to the court that, putting aside the question of a duty to warn, there may be causation problems that were not fully briefed and which may be dispositive on the issue. So, the court requested further briefing on causation.
We’ll be on the lookout for further ruling after the supplemental briefing, but for now we will give you our unsolicited thoughts. There are many things in life that make sense when done after the main event. Like reheating those Thanksgiving leftovers or sending a thank-you card. But issuing a post-sale duty to warn about an implantable medical device that was implanted years before you even owned the product? That’s not one of them. That’s more like being asked to apologize for a joke someone else told at a party you weren’t invited to.
Remember, Coopersurgical did not make the device implanted in these plaintiffs, did not sell the device implanted in these plaintiffs, did not profit from the device implanted in these plaintiffs, and, crucially, did not even own the product’s NDA until long after the device had been implanted. In this scenario, we agree with the judge that it is nearly impossible to discuss the duty without examining causation. Because whatever warning plaintiffs claim should have been made, the reality is Coopersurgical could not have issued that warning until long after plaintiffs’ doctors made the medical decision to prescribe the IUDs.
Even if we play along with the idea that there can be a post-sale duty to warn imposed on a successor, causation immediately collapses. A warning issued years after implantation cannot possibly influence the prescribing decision of a surgeon who acted years earlier. Absent time-travel or wormhole technology, there is simply no causal pathway.
Not surprisingly, we are not fans of post-sale duties to warn generally. But context matters. A post-sale duty to warn makes sense only when the party being saddled with the duty had some ability—actual, practical, temporal—to affect the risk. When the defendant purchased the NDA years after implantation, that ability is precisely zero. The entire concept of post-sale warnings assumes there is a practical way to reach users. That might make sense for toasters, leaf blowers, or lawn chairs. With IUDs, and many implanted devices, by the time a successor company enters the picture, the device is: already implanted, already functioning, and past the point where any newly added warning could possibly influence the clinical decision that put it there.
In the end, the law should stay grounded in reality. Post-sale duties should apply to those who had control at the time the risk could be avoided—not to those who merely entered the story years later. Because we can’t expect warnings to travel backward in time. Not even the Restatement contemplates that. And unless the defendant has secretly been hiding a flux capacitor, neither should the courts.