As per QR&O 19.015 and 19.02
"19.015 - LAWFUL COMMANDS AND ORDERS
Every officer and non-commissioned member shall obey lawful commands and orders of a superior officer.
(A) The expression "superior officer" includes a non-commissioned member. (See article 1.02 - Definitions
(B) Usually there will be no doubt as to whether a command or order is lawful or unlawful. In a situation, however, where the subordinate does not know the law or is uncertain of it he shall, even though he doubts the lawfulness of the command, obey unless the command is manifestly unlawful.
(C) An officer or non-commissioned member is not justified in obeying a command or order that is manifestly unlawful. In other words, if a subordinate commits a crime in complying with a command that is manifestly unlawful, he is liable to be punished for the crime by a civil or military court. A manifestly unlawful command or order is one that would appear to a person of ordinary sense and understanding to be clearly illegal; for example, a command by an officer or non-commissioned member to shoot a member for only having used disrespectful words or a command to shoot an unarmed child.
(D) With respect to riots, subsection 32(2) of the Criminal Code
(Revised Statutes of Canada, 1985, Chapter C-46
"32. (2) Every one who is bound by military law to obey the command of his superior officer is justified in obeying any command given by his superior officer for the suppression of a riot unless the order is manifestly unlawful."
19.02 - CONFLICTING LAWFUL COMMANDS AND ORDERS
(1) If an officer or non-commissioned member receives a lawful command or order that he considers to be in conflict with a previous lawful command or order received by him, he shall orally point out the conflict to the superior officer who gave the later command or order.
(2) If the superior officer still directs the officer or non-commissioned member to obey the later command or order, he shall do so.