One could easily conclude that there is no need for a separate defense of product misuse. After all, what is the misuse of a product if not contributory negligence (or, under the modern standard, comparative negligence)? Nevertheless, Michigan courts have found manufacturers of products liable for failing to guard against their misuse, and not allowed that misuse to reduce the award even under comparative negligence standards.

In Crowther v. Ross Chemical & Manufacturing Co., [66] the plaintiff suffered injuries from sniffing glue manufactured by the defendant. The Court found that the manufacturer had a duty to warn the plaintiff of possible ill effects of glue-sniffing, ignoring the argument, raised by the defendant, that a warning would have been worthless since the plaintiff intentionally sniffed the glue in order to get "high", and knew that doing so entailed certain health risks.

This decision came hot on the heels of the Court of Appeals decision in Byrnes v. Economic Machinery Corp., [67] holding the defendant liable for failing to guard against foreseeable misuse of the product. Two years later, the Court consolidated the thesis of these decisions in Thomas v. International Harvester Co. [68] In this case, the plaintiff, after reading a warning on a box of bearings, proceeded to act against that warning by hitting a bearing with a hammer. The bearing shattered and a piece flew into his eye. The Court adopted the position that the defendant was liable for damages resulting from any foreseeable use of the product, not merely the intended use of the product. Based on that rationale, one could safely infer that placing a warning on the package was conclusive evidence of the foreseeability of misuse. Yet not placing a warning would violate the standard of Ross Chemical. In other words, despite its protestations that Michigan does not accept strict liability, the court has imposed such liability, but with no affirmative defenses and little regard for causation.

Once again, the effects of this rule are to prohibit manufacturers from controlling their liability, to promote adverse selection of the risk pool by imposing a uniform "insurance cost" on the manufacturer, to be passed on to consumers, and to create uncertainty of liability, since manufacturers must now engage in a sort of mind-reading game, trying to predict every possible misuse of the product. Indeed it is not clear, in International Harvester, how the manufacturer could have prevented the misuse, even had he foreseen it. Presumably, his only alternative was to make sturdier bearings, thus driving low cost bearings out of the market. If bearings could not be made sturdier, those who used them safely would be forced to pay a higher price until they chose not to use bearings at all, in which case they would leave the risk pool and begin the process of adverse selection.