What was the context of the situation?

How did you respond to her?

How did she respond to you?

Why do you think you or your friend misread her?

I'm intrigued to find out why so many men misinterpret a woman being friendly as a sign of flirtation. I wonder if it's a confusion about what flirtatious means. Or maybe it's not realising the context of a woman being flirtatious like a waitress looking for tips. Or maybe it's just a general lack of social intelligence.