> Violent retribution by one private individual against another is already a right in many places if you're defending yourself

If Person A violently attacks Person B, then Person B has a right to defend themselves on the legal theory that Person A instigated the violence. "Credible threat" clauses muddy the line, but continue to rest on the pedestal of reaction versus action [1].

Here a court gave a company the right to instigate violence against the defendant. At least to this American, that's absurd.

[1] http://cji.edu/site/assets/files/1921/actionversusreaction.p...

Yes, and to this American, I assume I'm person B and in my rights to resist if they instigate and are not carrying a badge.

Maybe I am misunderstanding, but doesn't a bail bondsman do something similar in how extreme it is in the US too?

Note that self-defence is a defense, not a justification. It doesn't stop you from being taken to court, because you still were involved in something the law considers a crime. Your actions being self-defence just mean that the judge will likely find that there is reasonable doubt whether you were, in fact, committing murder. You might still have been committing murder! You might have set the other guy up to attack you so you could kill him, like with the old custom of professional "hired gun" duelists. But, since the other guy did attacked you first, it's (usually) impossible to prove that that's why you did it, rather than it just being because you were, in fact, trying to save your own life. (Unless you left written documentation of your nefarious plots somewhere.)

Fun fact: this is also true of "Fair Use" in copyright suits—it's also a defence, not a justification. If you put a 30-second sample of someone else's song in your song, they can still sue you, and waste your time and money in court! They just probably won't win, in the end. But if they have a lot more money than you, you might plea anyway.

Retribution and self defense are distinct motives. The former is about justice and the latter is about protection.