When an original warrant voucher produced for a claim is defective from the want of any certificate or other document which ought to have accompanied it, the comptroller may, upon proof being made to the comptroller’s satisfaction that the public accountant did not wilfully neglect to procure the certificate, or document, and that the sum specified in the warrant voucher has been actually and properly incurred as a state liability, admit the warrant voucher as sufficient evidence of liability, and allow the amount to be paid.