(a) A savings bank doing business in this state may continue to recognize the authority of an attorney-in-fact authorized in writing to manage or withdraw money from a deposit account of a member until the savings bank receives written or actual notice of the revocation of that authority.
(b) For purposes of this section, written notice of the death or adjudication of incompetency of a member is considered to be written notice of revocation of the authority of the member's attorney-in-fact.