A person who is or was a director, trustee or member of a juristic person at the time of the commission by that juristic person of an offence in terms of this Act is himself or herself guilty of the said offence, and is liable, on conviction, to the penalty specified if the offence in question resulted from the failure of the director, trustee or member to take all steps that were necessary under the circumstances to prevent the commission of the offence, as long as the proof of the said offence by the juristic person constitutes evidence on the face of it, that the director is guilty in terms of this section.