CA Civ Code Section 9410

(a)

The affidavit and counteraffidavit shall be filed with the court by the public entity and shall constitute the pleadings, subject to the power of the court to permit an amendment in the interest of justice. The affidavit of the direct contractor shall be deemed controverted by the counteraffidavit of the claimant, and both shall be received in evidence.

(b)

At the hearing, the direct contractor has the burden of proof.