Just for the record, here is the CARS reference:
Starting and Ground Running of Aircraft Engines
602.10 (1) No person shall start an engine of an aircraft unless
(a) a pilot's seat is occupied by a person who is competent to control the aircraft;
(b) precautions have been taken to prevent the aircraft from moving; or
(c) in the case of a seaplane, the aircraft is in a location from which any movement of the aircraft will not endanger persons or property.
(2) No person shall leave an engine of an aircraft running unless
(a) a pilot's seat is occupied by a person who is competent to control the aircraft; or
(b) where no persons are on board the aircraft,
(i) precautions have been taken to prevent the aircraft from moving, and
(ii) the aircraft is not left unattended.
Phil