(a) This section applies only to an act performed by a qualified executor or administrator in that capacity and in conformity with the law and the executor's or administrator's authority.
(b) An act continues to be valid for all intents and purposes in regard to the rights of an innocent purchaser who purchases any of the estate property from the executor or administrator for valuable consideration, in good faith, and without notice of any illegality in the title to the property, even if the act or the authority under which the act was performed is subsequently set aside, annulled, and declared invalid.