Where a person accused of an offence under this Act proves that in the ordinary course of his employment, he has acted without any intention to commit the offence and having taken all reasonable precautions against committing the offence charged, he had, at the time of the commission of the alleged offence, no reason to suspect the genuineness of the act so charged as an offence and on demand made by or on behalf of the prosecutor, he gave all the information in his possession with respect to the persons on whose behalf the offence was committed, he shall be acquitted.