"It is clear that the ultimate employer is not responsible for the acts of an independent contractor merely because what is to be done will involve dangers to others if negligently done. The incidence of liability is limited to certain defined classes, and for the purpose of this case it is only necessary to consider that part of this rule of liability which has reference to extra-hazardous acts, that is, acts which, in their very nature, involve in the eyes of the law special dangers to others …"
"There are indeed certain categories of cases in which an occupier is under such a primary duty to others that he in effect warrants the safety of his property against those who are injured by what happens upon it, or alternatively is personally responsible for having any work on it done in a competent manner even if he selected a competent independent contractor."
"The fact of insurance would go to their competence. If the firm did not hold itself out as being insured this would reflect both on their ability to meet any claim and, in addition, suggest that they were unlikely to be a reputable firm which could properly be entrusted with the responsibility of supplying and operating the ‘splat-wall’."
“It may therefore be inferred that an occupier might, in certain circumstances, be liable for something done or omitted to be done on his premises by an independent contractor if he did not take reasonable steps to satisfy himself that the contractor was competent and that the work was being properly done. It would not ordinarily be reasonable to expect an occupier of premises having engaged a contractor whom he has reasonable grounds for regarding as competent, to supervise the contractor’s activities in order to ensure that he was discharging his duty to his employees to observe a safe system of work. In special circumstances, on the other hand, where the occupier knows or has reason to suspect that the contractor is using an unsafe system of work, it might well be reasonable for the occupier to take steps to see that the system was made safe.”
“It is possible to envisage circumstances in which an occupier of premises engaging the services of an independent contractor to carry out work on his premises may, as a result of his state of knowledge and opportunities of supervision, render himself liable to an employee of the contractor who is injured as a result of the defective system of work adopted by the employer. But I incline to think that his liability in such case would be rather that of joint tortfeasor that of an occupier.”
“I recognise that there may be special circumstances which may render another person liable to the injured man together with his employer, as when they are, for some reason, joint tortfeasors, but such a situation appears to me to be quite different.”
“[T]he traditional common law response to the creation of a special danger is not to impose strict liability but to insist on a higher standard of care in the performance of an existing duty.”