Their comment wasn’t about what was legally right. I thought the part where they said something like “regardless of whether it is by courts doing things properly, by courts doing things improperly, or by some vigilante” made that clear enough?

Whether someone morally deserves a punishment for a crime depends on whether they actually did it, not on whether they are considered innocent in the eyes of the law.

Of course, I don’t generally support vigilantism , so I don’t think people should try to make other people get what they think the other people deserve as punishment. But, that doesn’t mean that people can’t deserve worse than the law prescribes, just that people shouldn’t like, try to deliver what they think the deserts are.

That is just the "legal" system. Not whether someone is morally guilty or not.

Hitler was never convicted of the holocaust in a court of law. Does that make him morally innocent? No.

Bin Ladin was never convicted of 9/11 in a court of law. Does that make him morally innocent? No.