What is the test for a failure to warn theory in a product liability case?

Courts in some jurisdictions have applied a heeding presumption to the causation element of product-liability cases based on a failure to warn theory. (See Coffman v. Keene Corp. (1993) 133 N.J. 581, 600-603 (Coffman), and authority collected there.) In those jurisdictions, the plaintiff is "afforded the use of the presumption that he or she would have followed an adequate warning had one been provided, and . . . the defendant in order to rebut that presumption must produce evidence that such a warning would not have been heeded." (Id. at p. 603.) Thus, use of this rebuttable heeding presumption shifts the "plaintiff's burden of proof on the issue of causation as it relates to the absence of a warning." (Ibid.)