Tort Law - Trespass
Trespass to the Person - Defences
Defence of Others
The law of self defence extends to defending not only oneself, but any other person, and is specifically applicable to the work of a security guard or body guard. It is lawful to intervene to the hurt or injury of an attacker who is attacking someone else. The same rule apply as in self defence – the threat must be credible or the danger real, what is done to repel the attack must be reasonable, and any other viable option short of counter-attack must be tried first.
Public Necessity, Private Necessity and Prevention of Suicide
The defence of necessity crosses over many different laws, protecting people who have acted in breach of a law for purposes of readily apparent emergency. However authority on it is not entirely certain and it is seldom used. Necessities can include preventing suicide or serious harm to or from a third party. It would not include any reason that would be seen as trivial or capricious. A good case on this is In Re F which dealt with a psychiatric patient who was sterilised to prevent unplanned pregnancies, but not in a fit state of mind to give or withhold consent...
ORDER FOR FULL TEXT.
Is Provocation a Defence?
As it stands, where an attacker is provoked by the victim, the sum claimable in exemplary damages (for particularly bad behaviour by the defendant) is reduced proportionally to the degree of provocation. Commonsense dictates that provocation should be a complete defence to trespass to the person, so that compensatory damages can be reduced also, and even, a claim defeated altogether in circumstances of sufficient severity. Everyone knows that to attack or threaten another person is a lesser moral offence, if it was in response to a seriously provocative act on the part of the victim. The law, however, sees this differently. In Fontin v Katapodis, it was ruled by the High Court that provocation is not available as a defence for the assailant. This ruling has held sway across the common law world and courts have continually expressed a high-minded attitude toward the use of violence.
Importantly, because Fontin was a ruling of the High Court, no other court in Australia can overrule it. The author is of a view, however, that this law can and should be overruled, but it would take a very serious case indeed to warrant going to the High Court to have a law from a prior decision overruled...
ORDER FOR FULL TEXT.
 In Re F (Mental Patient: Sterilisation)  2 AC 1.
 Fontin v Katapodis (1962) 108 CLR 177.
 Pingree, Andrew, Provocation as a Complete Defence to Trespass to the Person (2010) 15:2 DLU 205.