"Evidence of subsequent remedial measures is not admissible to prove negligence or culpable conduct in connection with the event. However, Rule 407 does not require the exclusion of evidence of subsequent measures when offered for another purpose, such as proving ownership, control, or feasibility of precautionary measures, if those issues are controverted, or impeachment. Rule 407 is based on the policy that individuals should be encouraged to improve, or repair, and not be deterred from it by the fear that if they do so their acts will be construed into an admission that they had been wrongdoers. Benton v. Hillcrest Foods, Inc., 136 N.C. App. 42, 52, 524 S.E.2d 53, 60-61 (1999) (citations and quotation marks omitted).