evidence offered “for impeachment or to prove other controverted matters, such as ownership, control, or feasibility of precautionary measures.” Pa.R.E. 407. Generally, courts have defined feasibility in this context more broadly than does Langston, to encompass not only technological possibility, but also considerations of cost and practicality and technological possibility. Given the scope of such definition, however, courts have advised that it should be applied cautiously in (5th Cir.1989)). Where, however, a defendant’s evidence and arguments are framed in categorical terms, are presented in the form of superlatives, or, more generally, upset the balance of fairness that Rule 407 seeks to maintain, courts have found the exceptions applicable. See, e.g., Wood, 70 F.3d at 1208 (<HOLDING>); cf. Muzyka v. Remington Arms Co., 774 F.2d
holding that where the defendants expert described the product design using superlatives namely the safest design you could possibly put on the machine the plaintiff should have been permitted to impeach the expert by inquiring why the safest design possible was modified following the plaintiffs accident holding that using a trade secret to produce a design for which a patent application is then submitted and using a product design to procure financing for development of that product constitute use holding that district court did not abuse its discretion in refusing to permit a design defect products liability expert to submit an untimely addendum stating a new claim of failure to warn after defense expert refuted the basis of original design defect opinion holding that an expert could testify that unguarded elevator buttons constituted a design defect despite the experts lack of a specific background in design and manufacture of elevators holding that in the context of construction litigation regarding the alleged negligence of design professionals a tort action for negligent misrepresentation alleging damages based purely on economic loss is not available to a party in privity of contract with a design professional