Morality of arrest?

I don’t think a person accused of murder would face a possible punishment of execution in a libertarian society.

What exactly do you mean by “functioning”? I’m finding it hard to make sense of such a vague term.

No, I don’t think it is.

No, that wasn’t your question. You asked whether it was justifiable for Bob to use force against Mike in order to get restitution. That question had nothing in it about any standard for determination.

There are currently three standards of guilt used in American jurisprudence: beyond a reasonable doubt, clear and convincing evidence, and preponderance of evidence. All three originated in English common law. The former applies to criminal cases, while the latter two apply to civil cases. I’m honestly not sure which of these three would be used in a libertarian legal system, or in which cases they’d each be used. However, I agree with you that the absolute certainty standard is obviously unworkable. My point was in no way to challenge that assertion.

Again, your question was simply about justifiability. So I figured you were asking a moral question, not a legal one. Furthermore, I never said that it’s never justifiable to use defensive violence against someone unless he’s consented. That’s a pure strawman of what I said. And as an aside, I personally don’t like using the term “punish” in this context, as I view that term as meaning “imposing pain for its own sake”. In other words, I don’t see “punishment” as involving restitution.