R. v. Miller  1 All E.R. 978 (H.L.)
Miller went out for a few drinks and came back to a place where he was staying to sleep. He lay on the mattress and fell asleep with a lit cigarette. He awoke to find the mattress on fire and moved to the next room and went back to sleep. The F.D. arrived. Miller said he just left the fire because he had nothing to put it out. He was charged with arson.
Does not trying to put out the fire make Miller guilty of arson?
Yes. Appeal dismissed; trial decision confirmed.
Lord Diplock – I would adopt the duty theory as being the easier to explain to a jury. When a person becomes aware of events that occur because of his own act, he must try to prevent or reduce the risk of damage himself or by sending for help from the fire brigade.
Moore v. R.  1 S.C.R. 195
Moore had run a red light on his ten-speed bike and then obscenely rebuffed a police officer when the latter told him to stop in order to write him a ticket. Moore was charged with unlawfully and wilfully obstructing a Peace Officer in the execution of his duty by failing to give his name as required by the Motor-vehicle Act.
Does Moore have a duty to identify himself and did he obstruct the constable in the exercise of his duties by refusing to identify himself?
Yes. Appeal dismissed.
The constable witnessed Moore committing an infraction and could only have arrested him for it after identifying him so that Moore might be the subject of summary conviction proceedings.
There is a strong dissent in this case by Dickson J. (Estey J. concurring) who held that there is neither a common-law nor statute-based duty for a person to identify oneself.
Furthermore, Dickson J. argues, the power of arrest is such that the constable could have arrested Moore in order to establish his identity and therefore it cannot be said that Moore is guilty of the serious offence of obstructing the constable.
R. v. Thornton  3 C.R. (4th) 381 (Ont. C.A.)
Thornton donated blood twice knowing that he was HIV-positive. He was charged with committing a common nuisance according to Criminal Code. The Crown argued that by failing to discharge a “legal duty”, he endangered the lives, safety, or health of the public. The trial judge found a legal duty by characterizing donating blood as involvement in a medical procedure (s. 216).
Did Thornton have a legal duty arising out of the common-law to inform the Red Cross of his HIV status?