Any decree entered pursuant to the provisions of section 4301 of this code (relating to appointment of temporary fiduciary) shall remain in force for the period specified in the court's original order or until revoked by the court upon petition and no act done by any substituted fiduciary pro tem or cofiduciary or cofiduciaries while such decree is in force shall be impeached on the ground that fiduciary temporarily removed was not acting.
20 Pa.C.S. § 4304