Me. Rev. Stat. tit. 20-A, § 10965

Evidences of indebtedness bearing duly authorized signatures of officers or officials holding office on the date of signing shall be valid and binding obligations, notwithstanding that before the delivery of and payment for the obligation any or all persons whose signatures appear on the evidences of indebtedness shall have ceased to be such officers or officials. The validity of evidences of indebtedness shall not be dependent on nor affected by the validity or regularity of any proceedings to acquire any project financed with the proceeds of evidences of indebtedness, or to refund outstanding evidences of indebtedness, or otherwise taken in connection with the financing transaction.