(a) A privilege under G.S. 1-657 may be waived in a record or orally during a proceeding if it is expressly waived by all parties and, in the case of the privilege of a nonparty participant, it is also expressly waived by the nonparty participant.
(b) A person that makes a disclosure or representation about a collaborative law communication which prejudices another person in a proceeding shall not assert a privilege under G.S. 1-657, but this preclusion applies only to the extent necessary for the person prejudiced to respond to the disclosure or representation.