4. An engineer is disqualified from being commissioned under paragraph 3 in relation to a high-consequence or medium-consequence reservoir if the engineer—
(a)was commissioned under section 33(2) in relation to the making of the decision which is the subject of the review,
(b)prepared the document,
(c)is, or has previously been an employee of any person who is, or has previously been, a reservoir manager of the reservoir.