Cal. Penal Code § 26361
Section 26350 does not apply to, or affect, the open carrying of an unloaded handgun by any peace officer or any honorably retired peace officer if that officer may carry a concealed firearm pursuant to Article 2 (commencing with Section 25450) of Chapter 2, or a loaded firearm pursuant to Article 3 (commencing with Section 25900) of Chapter 3.