If:
(a) on ART review of a decision, the ART sets the decision aside under section 105 of the ART Act; and
(b) the Secretary or the ART, as the case may be, is satisfied that an event that did not occur would have occurred if the decision had not been made;
the Secretary or the ART may, if satisfied that it is reasonable to do so, treat the event as having occurred for the purposes of the family assistance law.