21 It is necessary to consider the circumstances in which knowledge gained by Moray & Agnew would be said to be knowledge of the prosecutor. The defendant relied upon the judgment of Hutley JA in the New South Wales Court of Appeal in Ford Excavations Pty Ltd v Do Carmo (1981) 2 NSWLR 253. Whilst the decision of the Court of Appeal was overturned on appeal to the High Court of Australia (Do Carmo v Ford Excavations Pty Ltd (1984) 154 CLR 234) the judgment of the members of the High Court does not impact upon what was said by Hutley JA concerning the question of agency and the extent to which the knowledge of the agent becomes knowledge of the principal, especially in the context of a solicitor/client relationship. Those proceedings were concerned with the provisions of the Limitation Act 1969 (NSW) and involved a consideration of whether material facts of a decisive character relating to the cause of action were or were not within the means or knowledge of an applicant for an extension of time in which to commence proceedings. It was necessary for the Court to consider the relevance of an applicant having taken advice from a legal practitioner as to whether or not there was a cause of action. The applicant in those proceedings had consulted a solicitor to whom he had been referred by his trade union. In discussing the knowledge of the solicitor and the knowledge of the applicant as client Hutley JA said:
"The solicitor consulted is the agent of the worker, both to acquire the requisite knowledge to enable the worker to bring a case and to apply such knowledge as he possesses to the task. Where a person employs an agent the knowledge of the agent within the scope of his authority is the knowledge of the principal provided the agent is bound to inform the principal of what he has learned. As Bowstead on Agency, 14th ed (1976), Article 106(2), at p 334, says:
'When any fact … material to any … matter in respect of which an agent is employed, comes to his knowledge in the course of such employment, and is of such a nature that it is his duty to communicate it to his principal, the principal is deemed to have notice thereof as from the time when he would have received such notice if the agent had performed his duty, and taken such steps to communicate the fact … as he ought reasonably to have taken …'.
The knowledge of the principal acquired through the agent is not constructive knowledge, it is actual knowledge. The exception to the treatment of the knowledge of the agent as aggregated, with that of the principal, namely, that the honest statements of a principal and of an agent cannot be added together to make a case fraud really proves the rule, actual mala fides being required to establish fraud: Armstrong v Strain [1952] 1 KB 232. Constructive knowledge covers a much wider range of events, eg, it includes knowledge which is not the actual knowledge of any party.
Any other rule would have quite strange results. A person who had appointed an agent to investigate a matter would never have knowledge of the facts discovered by the agent if they were not communicated to him. It is not infrequently the case that psychiatrists are only prepared to report on the mental disorder of a patient to the patient's own legal advisers on the basis that the information is not communicated to the patient himself, as his actual knowledge might interfere with his own rehabilitation. A client who had actual knowledge of every material fact, except the identity of the person against whom his cause of action would lie, the discovery of which he left to his solicitor, would be entitled to an extension of time because even though the solicitor discovered that fact, he did nothing to communicate it to him within the statutory period. In both cases, he by hypothesis does not know the fact and has taken reasonable steps to ascertain it.
Where a solicitor acting for a client obtains knowledge or has knowledge as part of his general fitness to advise the client of the material facts relating to his client's cause of action, those facts are, in my opinion, part of the actual knowledge of the client. For a trade union solicitor, this includes the state of the art in industrial safety. Whether or not the respondent knew anything about the well-known practices in the industry is, in my opinion, irrelevant. There is no reason here to infer that the solicitor for a trade union, whose members operate in a field in which silicosis is likely to be produced unless proper precautions are taken, does not know of the safety precautions appropriate to that industry from time to time as a necessary concomitant of taking on the responsibility of advising. In other words, there was available to the notional legal adviser a further fact, namely, that the inhalation of dust from which the respondent suffered was at all relevant times preventable by steps which were not inconsistent with the performance the work he was engaged to do. On this basis, a competent legal adviser should have no doubts. (at 266-7)