(a) It is no defense to prosecution under Section 37.02 (Perjury) or 37.03 (Aggravated Perjury) that the oath was administered or taken in an irregular manner, or that there was some irregularity in the appointment or qualification of the person who administered the oath.
(b) It is no defense to prosecution under Section 37.02 (Perjury) or 37.03 (Aggravated Perjury) that a document was not sworn to if the document contains a recital that it was made under oath, the declarant was aware of the recital when he signed the document, and the document contains the signed jurat of a public servant authorized to administer oaths.