I think I know who you're talking about, and I wouldn't give it another thought, frankly. She doesn't think about the effect of her words on anyone's feelings,yet somehow has one of the most sensitive natures around and takes it very hard if she feels ignored or talked down to. She's lost a lot of friends in varying fandoms because of her drama and rudeness. And if I'm right about who it is, she would have been a lot more polite to you if she thought you were big in the fandom, which just goes to show the type of person you're dealing with.

Either way, I'm so sorry you had such a bad encounter with whoever it was. It's such a shame when people are so needlessly thoughtless. You didn't do anything wrong, and only people who have nothing to feel good about in their own lives treat others that way.