13.1. The board may, of its own initiative or on the application of any interested person, revise or revoke any decision it has made(1) where a new fact is discovered which, if it had been known in due time, might have justified a different decision;
(2) where a substantial or procedural defect is likely to invalidate the decision;
(3) where the applicant, being a party to the issue, was, for sufficient reasons, prevented from being heard.