6Pleading of mistake, act of third party, etc., as defence.N.I.
In proceedings for any offence under section 3 in respect of any produce it shall be a defence for the person charged to prove—
(a)that the commission of the offence was due to the act or default of some other person, or to a mistake, or to an accident or some other cause beyond his control; and
(b)that he took all reasonable precautions and exercised all due diligence to avoid the commission of such an offence in respect of that produce by himself or any person under his control.