Cal. Prob. Code § 716

Notwithstanding Section 710, if an attorney has given written notice to the depositor, and has obtained written acknowledgment from the depositor, in substantially the form provided in Section 715, and the requirements of subdivision (a) of Section 732 are satisfied, the attorney, and a successor attorney that accepts transfer of a document, shall use at least slight care for preservation of a document deposited with the attorney.