18.—(1) In proceedings for an offence under article 13, 16 or 17 it is a defence for A.B Ports to prove that it took all reasonable precautions and exercised all due diligence to avoid the commission of such an offence.
(2) If in any case the defence provided by paragraph (1) involves the allegation that the commission of the offence was due to the act or default of another person, A.B Ports shall not, without leave of the court, be entitled to rely on that defence unless, within a period of seven clear days before the hearing, it has served on the prosecutor a notice in writing giving such information identifying, or assisting in the identification of, that other person as was then in its possession.