I think you go a bit far, but I agree somewhat.

I was picked on a fair bit in school. The nature of "zero-tolerance" meant that fights were quick. I recall one day just being shoved into a a door threshold unexpectedly. I had had it at that point from this person, so I took my heaviest book out of my bag and slammed him in the head with it as he was already walking away triumphantly. Looking back, he could have been seriously injured. Many people witnesses and laughed at him.

He never bothered me again.

But how can you know someone will leave you alone or just escalate things?