EVID § 1128

Any reference to a mediation during any subsequent trial is an irregularity in the proceedings of the trial for the purposes of Section 657 of the Code of Civil Procedure. Any reference to a mediation during any other subsequent noncriminal proceeding is grounds for vacating or modifying the decision in that proceeding, in whole or in part, and granting a new or further hearing on all or part of the issues, if the reference materially affected the substantial rights of the party requesting relief.