(1) Where a bill is intentionally cancelled by the holder or his agent, and the cancellation is apparent thereon, the bill is discharged.
(2) In like manner any party liable on a bill may be discharged by the intentional concellation of his signature by the holder or his agent. In such case any indorser who would have had a right of recourse against the party whose signature is cancelled is also discharged.
(3) A cancellation made unintentionally, or under a mistake, or without the authority of the holder is inoperative; but where a bill or any signature thereon appears to have been cancelled the burden of proof lies on the party who alleges that the cancellation was made unintentionally, or under a mistake, or without authority.