I understand how you feel, I've been in similar situations. I once had a male customer introduce himself to me, ask my name and then inquire if I was married. I was like...what? I'm working. Who does this? Seriously, who does this? It was so uncomfortable and awkward.

I'm going with what was said, about kindness and friendliness being mistaken as a flirtation. It happens a lot. I doubt you intended to give anyone any kind of impression. Don't beat yourself up about it, he acted according to whatever he was thinking and feeling. I think you handled it well. I would honestly, go off and hide. I did tell my co-workers what happened so if the guy came in, I'd have them talk to him and I'd go someplace where I couldn't be seen. lol