Another unwarranted assumption:

"Multi-lingual people usually..."

Any sentence such as this should send up warning flags; you are extrapolating from the specific to the general: "I, and those of my acquaintance, usually respond in the language with which we are addressed; therefore, all other multilingual people do also." False; try speaking Spanish or German to me while in America and listen to what language I use to respond, even though I am capable of responding in either of them. Strangely enough, if you speak French to me, I will respond in French. Weird, ain't I?

Anyway, your conclusion that she acted like a bitch was also falsely drawn; why is a female automatically a bitch because she doesn't want to be hassled?
What would you have called a male who responded that way?

Thanks for taking the time to explain your reasoning, but remember the Cartesian Fallacy: mistaking clear reasoning for correct reasoning; they are not necessarily the same.