some people are just more ready for confrontation. I've seen it from all types, but normally just older people.

that said maybe because you couldn't understand her accent she got mad. I had an Indian friend/coworker who had a very thick accent, she was fluent in english but sometimes people had a hard time understanding her and this would make her really mad. but we live in a diverse area, just think you'll have a chinese man come in the store with a thick accent himself, and she has a thick indian accent, and they're both struggling to communicate. the ironic thing is that she would get mad at others when they had thick accents and say they were hard to understand, even saying they should learn english.

in your case it seems like the lady might have got upset you didn't understand her accent, and it doesn't seem like you attempted to understand her. she probably deals with that often and it can be frustrating never being understood, so she took it out on you.

If I were you I think I would have just let her go inside and let the staff deal with it.