I train martial arts since being a small boy and no one ever called the police because of me. So I am not sure about that:

"Besides, I bet you are fully aware that the point GP was making was that his training made him dare say something where he before wouldn't. "

And I know a lot of people, bolstering their martial arts skills to impress and supress people. Once or twice I had to restrain some.

Still - repeatedly engaged talking to someone who don't wants to be talked with - can be defined as harrasment either way. And close to self justice in this case.

I know the urge for it sometimes. But .. that just means trouble.

(side note: Judo is not very effective as self defence)