For the purposes of Chapter 5 (commencing with Section 4300) of Part 2 of Division 4.5, in the case of a principal who is an absentee, an attorney-in-fact or third person shall be deemed to be without actual knowledge of the following:
(a) The principal’s death or incapacity while the absentee continues in missing status and until the attorney-in-fact or third person receives notice of the determination of the absentee’s death by the secretary concerned or the head of the department or agency concerned or the delegate of the secretary or head.
(b) Revocation by the principal during the period described in subdivision (a).