When, after an event, measures are taken which, if taken previously, would have made the event less likely to occur, evidence of the subsequent remedial measures is not admissible to prove strict liability, negligence, or culpable conduct in connection with the event. This rule does not require the exclusion of evidence of subsequent measures when offered for another purpose, such as proving controverted ownership, control, or feasibility of precautionary measures, or impeachment.
Tenn. R. Evid. 407
Advisory Commission Comments.
This rule and current Tennessee law exclude subsequent measures to remedy defects to prove negligence or culpable conduct. Illinois Central Railroad Co. v. Wyatt, 104 Tenn. 432, 58 S.W. 308 (1900). The rule adds, however, a specific exclusion in strict liability actions as well. Such is the majority federal view, including that of the Sixth Circuit. See Hall v. American Steamship Co., 688 F.2d 1062 (6th Cir. 1982) (admiralty). Manufacturers should be encouraged to improve product designs without fear of encountering damaging evidence.
A defendant who controverts ownership, control, or feasibility opens the door for the plaintiff to introduce subsequent remedial measures. Similarly, an expert who opines that a design could not be improved upon invites attack by the impeachment exception to this otherwise exclusionary rule.