A friend of mine told me something similar and I was absolutely outraged. And in her case, the guy didn't have the audacity to fake apologise afterwards-you must have been so uncomfortable and scared. (The 'you should be flattered' is outrageous!)

I'm the same-some women are good at snapping back with a witty retort but I'm silent/ leg it, as you can probably tell from the piece.So I understand when you say that you regret not giving him a piece of your mind. But no one really expects to be accosted in this way, after all. I only think it's important to do what feels safe to you in the moment.