In a proceeding for an offence against these regulations, a certificate that appears to be signed by or on behalf of a utility and contains a statement to the effect that—
(a) a stated thing was done by a stated person in accordance with an authorisation by the utility under regulation 6; or
(b) an authorisation by the utility under regulation 6 was subject to a stated condition at a stated time or date;
is evidence of the matters stated.