Cal. Labor Code § 2689

To facilitate the conduct of the hearing, the following procedures shall govern: (a) Upon good cause shown by a party, the chairperson shall be empowered to issue subpoenae duces tecum and ad testificandum. (b) Each party may be represented by an attorney at the party’s own expense. (c) The formal rules of evidence shall not be applicable, but any relevant evidence shall be admitted if it is evidence upon which responsible persons would rely in the conduct of serious business affairs. (d) All testimony shall be taken under oath. (e) No formal written records shall be kept unless one or both parties agree to employ at their own expense a qualified court reporter for that purpose. In such case, a copy of the record shall be provided to the panel and a copy shall be made available to the other party at the standard cost for such additional copies. (f) Those in attendance at the hearing shall be limited to the panel, the parties and their counsel, a court reporter, interpreters when requested by a party or the panel, and witnesses while testifying. (g) Upon the request of a panel member, the panel may allow a period, not to exceed three days following the conclusion of the hearing, during which time a party may submit otherwise admissible evidence not available during the course of the hearing.