Cal. Elec. Code § 15304

In jurisdictions using a central counting place, the elections official may appoint not less than three deputies to open the envelopes or containers with the materials returned from the precincts. If, after examination, any of the materials are incomplete, ambiguous, not properly authenticated, or otherwise defective, the precinct officers may be summoned before the elections official and examined under oath to describe polling place procedures and to correct the errors or omissions.