The neglected duty must be a legal duty (imposed by law or by contract) and not merely a moral obligation, and the omission to perform it must be the immediate and direct cause of death.
Legal relations of protector include husband to wife, parent to child, master to seaman, etc.
Beardsley had assumed no care or control over the woman.
Smithers v. R.  1 S.C.R. 506
Smithers is a black hockey player who, during an intense game, was subjected to racial insults by the deceased hockey player and the rest of the opposing team. Both Smithers and the deceased were ejected from the game after an abusive exchange of profanities. Smithers kept threatening that he was going to “get” the deceased. In the parking lot, Smithers caught up to the deceased and gave him a couple punches to the head and, as the deceased doubled up, a sucker kick to the stomach area. The deceased was DOA at the hospital. An autopsy revealed that the victim died from inhaling foreign materials in his vomit, which is a rare and unusual cause of death in the case of a healthy adolescent.
Did Smithers commit homicide (by any direct or indirect means) by causing the death of the teen? Was this death culpable because it was caused by an unlawful act?
Yes. Appeal dismissed; manslaughter conviction confirmed.
The evidence showed that the kick was at least a contributing cause of death, outside the de minimis range, and that is all that the Crown was required to establish. “Thin skull” rule may also apply in criminal matters as it does in civil matters.
R. v. F. (D.L.)  73 C.R. (3d) 391 (Alta. C.A.)
D.L.F. was a youth who drove dangerously while intoxicated and hit a pedestrian, who suffered bodily harm. The pedestrian was jaywalking and D.L.F. didn’t see him. The trial judge acquitted D.L.F. on account that his hitting the pedestrian was due to inattention and not dangerous driving.
Did D.L.F.’s dangerous driving cause bodily harm to the pedestrian?
Yes. Appeal allowed; conviction entered.
The trial judge had concluded that there was indeed dangerous driving and that while the pedestrian was jaywalking, D.L.F. should have seen him but did not.