Ex Parte Communications. 8 CCR § 10410

(a) No document, including letters or other writings, shall be filed by a party with the Workers' Compensation Appeals Board unless service of a copy thereof is made on all parties together with the filing of a proof of service as provided for in rule 10625. (b) When the Appeals Board or a workers' compensation judge receives an ex parte letter or other document from any party in a case pending before the Appeals Board or the workers' compensation judge, the Appeals Board or the workers' compensation judge shall serve copies of the letter or document on all other parties to the case with a cover letter explaining that the letter or document was received ex parte in violation of this rule. (c) No party shall discuss with the Appeals Board or a workers' compensation judge the merits of any case pending before the Appeals Board or that workers' compensation judge without the presence of all necessary parties to the proceeding, except when submitting a walk-through document in accordance with rule 10789. (d) All correspondence concerning the examination by and the reports of a physician appointed by a workers' compensation judge or the Appeals Board pursuant to Labor Code sections 5701, 5703.5, 5706 or 5906 shall be made, respectively, through the workers' compensation judge or the Appeals Board, and no party, attorney or non-attorney representative shall communicate with that physician regarding the merits of the case unless ordered to do so.