"Rule 408 provides that evidence of conduct or statements made in compromise negotiations is inadmissible. This rule does not, however, require the exclusion of evidence that is otherwise discoverable or offered for another purpose, merely because it is presented in the course of compromise negotiations. Renner v. Hawk, 125 N.C. App. 483, 492-493, 481 S.E.2d 370, 375-76 (citation omitted), disc. review denied, 346 N.C. 283, 487 S.E.2d 553 (1997).