28.—(1) Subject to regulations 6 and 29, on an application made by any party, the Commissioner who gave the decision in proceedings may set it aside where it appears just to do so on the ground that—
(a)a document relating to the proceedings was not sent to, or was not received at an appropriate time by, a party or his representative, or was not received at an appropriate time by the Commissioner; or
(b)a party or his representative was not present at a hearing before the Commissioner; or
(c)there has been some other procedural irregularity or mishap.
(2) An application under this regulation shall be made in writing to a Commissioner within one month from the date on which the office gave written notice of the decision to the party making the application.
(3) Unless the Commissioner considers that it is unnecessary for the proper determination of an application made under paragraph (1), the office shall send a copy of it to each respondent, who shall be given a reasonable opportunity to make representations on it.
(4) The office shall send each party written notice of a determination of an application to set aside a decision and the reasons for it.