Well answered! I commend your brain for its good responses. And the rest of you too, I suppose.

I'd guess it was the combination of somewhat stereotypical appearance and the brush-off that prompted the question. And-or maybe uninterested body language contributed. I wonder what particular brain pattern he has that didn't flag that question as inappropriate but still allowed him to put together cues that might suggest the conclusion.

[edit] Flag. FLAG. Of all the typoes to make.