In the settlement of the accounts of the commanding officer of a squadron for clothing and other military supplies, his affidavit may be received to show—

(1) that vouchers or squadron books were lost;

(2) anything tending to prove that any apparent deficiency of those articles was caused by unavoidable accident, or by loss in actual service without his fault; or

(3) that all or part of the clothing and supplies was properly used.

The affidavit may be used as evidence of the facts set forth, with or without other evidence, as determined by the Secretary of the Air Force to be just and proper under the circumstances.