A surveillance device warrant allows the following persons to carry out the activities authorised by it:
(a) any or all of the persons to whom it is directed:
(b) any assistant—
(i) who is called upon by a person specified in paragraph (a) to help him or her to carry out the activities; and
(ii) who, at all times that he or she is carrying out activities authorised by the warrant, remains under the supervision of a person specified in paragraph (a).