"I thought you were supposed to be in Paris" "I am in Paris" -Blowup

So I finally saw the movie. The poster hung on my wall for months. And now I have given that some validity. It was good. I sat down in the packed movie theater (first showing of the new print) and a couple of American girls sat down a few seats away from me. Then a nice old man with a bow tie scooted past the girls and sat next to me. The girls were chatting in English, and the old man rolled his eyes at me. I kind of laughed and he said in French:

Pour quoi tous les etrangers parlent tres fort?
Why do foreigners always talk so loud?

My feelings at this comment were mixed: I was flattered, he really thought I was french. But also slightly offended. Mostly I did not know how to respond. So i replied in my best french that I didn't know why. I think he figured me out.
I suppose there is some truth in what he said. But I would probably phrase it differently:

Why is it that French people talk so quietly?

I really don't know. He chalked it up to the fact that the Upper Class French have better manners than everyone else.
If you were wondering, he liked the movie, though he thought the end was too abrupt.