(a) they believe on reasonable grounds that force is being used against them or another person or that a threat of force is being made against them or another person;(b) the act that constitutes the offence is committed for the purpose of defending or protecting themselves or the other person from that use or threat of force; and
(c) the act committed is reasonable in the circumstances.
(2) In determining whether the act committed is reasonable in the circumstances, the court shall consider the relevant circumstances of the person, the other parties and the act, including, but not limited to, the following factors:
(a) the nature of the force or threat;
(b) the extent to which the use of force was imminent and whether there were other means available to respond to the potential use of force;
(c) the person’s role in the incident;
(d) whether any party to the incident used or threatened to use a weapon;
(e) the size, age, gender and physical capabilities of the parties to the incident;
(f) the nature, duration and history of any relationship between the parties to the incident, including any prior use or threat of force and the nature of that force or threat;
(f.1) any history of interaction or communication between the parties to the incident;
(g) the nature and proportionality of the person’s response to the use or threat of force; and
(h) whether the act committed was in response to a use or threat of force that the person knew was lawful.
(3) Subsection (1) does not apply if the force is used or threatened by another person for the purpose of doing something that they are required or authorized by law to do in the administration or enforcement of the law, unless the person who commits the act that constitutes the offence believes on reasonable grounds that the other person is acting unlawfully.