"Whether on the facts found we were right to conclude that the respondent had exercised all due diligence to avoid the commission of the offence."
"What amounts to the taking of all reasonable precautions and the exercise of all due diligence by a principal in order to satisfy the requirements of paragraph (b) of section 24(1) of the Act [I interpolate,Trade Descriptions Act 1968 whose provisions are identical for our purposes to those of the Licensing Act] depends upon all the circumstances of the business carried on by the principal. It is a question of fact for the Magistrates in summary proceedings or for the jury in proceedings on indictment."
"Where Parliament in creating an offence of 'strict liability' has also provided that it shall be a defence if the person upon whom the duty is imposed proves that he exercised all due diligence to avoid a breach of the duty, the clear intention of Parliament is to mitigate the injustice, which may be involved in an offence of strict liability, of subjecting to punishment a careful and conscientious person who is in no way morally to blame. To exercise due diligence to prevent something being done is to take all reasonable steps to prevent it. It may be a reasonable step for an employer to instruct a superior servant to supervise the activities of inferior servants whose physical acts may in the absence of supervision result in that being done which it is sought to prevent. This is not to delegate the employer's duty to exercise all due diligence; it is to perform it. To treat the duty of an employer to exercise due diligence as unperformed unless due diligence was also exercised by all his servants to whom he had reasonably given all proper instructions and upon whom he could reasonably rely to carry them out, would be to render the defence of due diligence nugatory and so thwart the clear intention of Parliament in providing it."
"Also behind the counter are with him [that is Mr Mehdipour] when he served the alcohol was the respondent's brother, who was the manager of the shop on the day. The Licensee of the premises was the respondent, who was not on the premises at that time."
"We were of the opinion that a small corner shop could not reasonably be expected to have in place all the systems that, for example, a supermarket would have in place."