N.C. Gen. Stat. § 1-567.34: Waiver of right to object.

A party who knows that any provision of this Article or any requirement under the arbitration agreement has not been complied with and yet proceeds with the arbitration without stating an objection to such noncompliance without undue delay or, if a time limit is provided therefor, within that period of time, shall be deemed to have waived any right to object. (1991, c. 292.)