What is the substantial causation test for the offence of manslaughter?

The substantial causation test requires that the accused play a very active role -- usually a physical role -- in the killing. Under s. 214(5), the actions of the accused must form an essential, substantial and integral part of the killing of the victim." Saunders, J. particularly highlighted the remainder of that paragraph: "[35] ... Obviously, this requirement is much higher than that described in Smithers v. The Queen, 1977 CanLII 7 (SCC), [1978] 1 S.C.R. 506, which dealt with the offence of manslaughter. There it was held at p. 519 that sufficient causation existed where the actions of the accused were "a contributing cause of death, outside the de minimis range". That case demonstrates the distinctions in the degree of causation required for the different homicide offences."