“It is trite law that a master is vicariously liable for the negligence of his servant committed in the course of and within the scope of the servant’s employment, but the application of this principle to the realities of a situation is fraught with considerable difficulties. The result is that ultimately each case will have to be determined on its own facts. In Goh Choon Seng v. Lee Kim Soo [1925] A.C. 550, the Privy Council held that an employer is responsible for damage caused by the negligent act of his servant in the course of performing the duties of his office even if the act incidentally involves a trespass which the employer has not authorised. In the course of the judgment of the Board, Lord Phillimore suggested a classification of the possible cases into three categories, in a passage which reads as follows [at p. 554]- “As regards all the cases which were brought to their Lordships’ notice in the course of the argument this observation may be made. They fall under one of three heads: (1) The servant was using his master’s time or his master’s place or his master’s horses, vehicles, machinery or tools for his own purposes: then the master is not responsible. Cases which fall under this head are easy to discover upon analysis. There is more difficulty in separating cases under heads (2) and (3). Under head (2) are to be ranged the cases where the servant is employed only to do a particular work or a particular class of work, and he does something out of the scope of his employment. Again, the master is not responsible for any mischief which he may do to a third party. Under head (3) come cases like the present, where the servant is doing some work which he is appointed to do, but does it in a way which his master has not authorized and would not have authorized, had he known of it. In these cases the master is, nevertheless, responsible.” I respectfully agree with this classification. It should, however, be understood that the three categories are not necessarily mutually exclusive of each other, in other words, they overlap or interlock to some extent.”