shall not subsequently determine the document is inadequate or invalid because of the lack of authority of any person signing the document on behalf of the applicant or any other individual, entity, or qualified pass through entity (as such term is defined in paragraph (5) of section 1001(a) of the Food Security Act of 1985 ( 7 U.S.C. 1308(a) )) or the documents relied upon were determined inadequate or invalid, unless the person signing the program document knowingly and willfully falsified the evidence of signature authority or a signature. (b) Affirmation (1) In general Nothing in this section prohibits the Secretary from asking a proper party to affirm any document that otherwise would be considered approved under subsection (a). (2) No retroactive effect A denial of benefits based on a lack of affirmation under paragraph (1) shall not be retroactive with respect to third-party producers who were not the subject of the erroneous representation of authority, if the third-party producers— (A) relied on the prior approval by the Secretary of the documents in good faith