California Code, Probate Code - PROB § 4308

(a) A third person who conducts activities through employees is not charged under this chapter with actual knowledge of any fact relating to a power of attorney, nor of a change in the authority of an attorney-in-fact, unless both of the following requirements are satisfied:

(b) Knowledge of an employee in one branch or office of an entity that conducts business through branches or multiple offices is not attributable to an employee in another branch or office.