The ground mentioned in section 17(2)(h) and section 18(2)(h) is taken not to be made out –

(a) unless –

(i) the person who made, or proposed to make, the decision was required by law to reach the decision only if a particular matter was or is established; and

(ii) there was no evidence or other material (including facts of which the person was or is entitled to take notice) from which the person could or can reasonably be satisfied that the matter was or is established; or

(b) unless –

(i) the person who made, or proposes to make, the decision based, or proposes to base, the decision on the existence of a particular fact; and

(ii) the fact did not or does not exist.