The filing of a motion for an order appointing a referee does not constitute a waiver of grounds for objection to the appointment of a particular person as referee under Code of Civil Procedure section 641, or objection to the rate or apportionment of compensation of the referee. Any objection to the appointment of a particular person as a referee must be made with reasonable diligence and in writing. The objection must be heard by the judge to whom the case is assigned, or by the presiding judge or the law and motion judge.
Cal. R. Ct. 3.925