Johnson v. Ridge Tool Manufacturing Co., 186 F.4th 478 (7th Cir. 2026), is a product liability decision involving a drain cleaning machine, not a prescription medical product. But that doesn’t mean that our clients won’t find it useful. A unanimous Seventh Circuit panel, interpreting Illinois law, affirmed summary judgment on both the plaintiff’s design and warning claims. Both affirmances have holdings that potentially apply to prescription medical product liability litigation.
First, the design aspect. That involves the quantum of alternative design evidence required by Illinois law. “In Illinois, a plaintiff’s case against a product manufacturer is supported by showing that a safer alternative product design was feasible.” Johnson, 184 F.4th at 485 (citation omitted). Plaintiff’s expert witness opined simply “pointed to competitor machines that already have the alternative design,” and asserted he needed to do no more. Id. We see that all the time. Johnson said “no” – that’s not enough. Somebody must have tested the claimed alternative.
We disagree. To be sure, testing an alternative design is unnecessary if it is already used in the marketplace. . . . But [our precedent] do[es] not hold that just pointing to competitor products is enough to admit an expert’s opinion. That a design exists, without more, cannot be the sole basis for an expert’s opinion. Yet that describes [this expert’s] report. To him, three comparators prove that an alternative design is feasible, so [defendant] should have incorporated that design when manufacturing the machine.
Id. at 486 (emphasis added). An expert that fails to test the alternative design s/he advocates needs to do a lot more to make up for that deficiency, such as: (1) evaluating the costs of the supposed alternative design, (2) the alternative’s “compatibility with existing systems,” (3) practical benefits of the existing design, (4) “publications” that “conclude that [the alternative] is important or necessary, and (5) comparative safety rates. Id.
Another possible way of validating a claimed alternative design without testing is whether the alternative, as opposed to the challenged design, conformed to industry standards. Once again, the plaintiff’s expert report in Johnson flunked the test:
[The expert] pointed to three other competitors that used [the alternative design]. The district court asked the right question: three out of how many machines? Three out of four with [the alternative] likely means that design is the industry standard; but three out of four hundred proves little. . . . [The expert’s report] lacks the denominator, which the district court correctly held against him.
Id.
As to warnings, the plaintiff offered an expert’s opinion attacking the adequacy of the instructions in the product manual. Johnson, 186 F.4th at 487. Slight problem with that – plaintiff “had not read the manual. So, he cannot establish that the alleged flaws caused his injury.” Id. So Johnson goes into our failure-to-read 50-state survey. But even more important, the Seventh Circuit recognized that an expert warning opinion is inadmissible unless the expert proposes an alternative warning:
[There is] a second deficiency with [this expert’s] report: it does not propose an alternative warning that she believes would have prevented [plaintiff’s] injury. Without discussing what designs would have effectively warned a user, any opinion about the ineffectiveness of the current warning is akin to talking off the cuff and not acceptable methodology. Though no single factor is dispositive under Rule 702, an expert’s failure to design or suggest to the court an alternative warning that would have been appropriate signals unreliability.
Id. (following Bourelle v. Crown Equipment Corp., 220 F.3d 532, 539 (7th Cir. 2000)). That holding favorably addresses another problem that we have encountered all too often in our defense of prescription medical product liability litigation – moving target warning “experts” that never identify what an adequate warning would have stated.
Illinois substantive law produced the same result on the warning claim:
Illinois courts have ruled that in failure-to-warn suits, alternative warnings are necessary to survive summary judgment. “To prevail,” a plaintiff “must establish that greater warnings would have prevented [the] injuries.” Said another way, plaintiffs cannot defeat something with nothing.
Johnson, 186 F.4th at 488 (quoting and following Muhammad v. Abbott Laboratories, Inc., 203 N.E.3d 1001, 1018 (Ill. App. 2022) (a case we couldn’t discuss because Bexis was working on it)). Alternative warnings also go to causation. “Without an alternative warning, we are left guessing whether a better one would have prevented [plaintiff’s] accident.” 186 F.4th at 489. Since the plaintiff didn’t read the existing warnings, “a more descriptive, and thus longer, label may have discouraged [plaintiff] from reading it.” Id.
So there you have it. Precedential Seventh Circuit holdings that: (1) under Rule 702 alternative design opinions that do no more than point to a competing design are inadmissible; and (2) under Illinois law, warning claims fail where the plaintiff does not offer an alternative warning.