The HR rep pulled me into an impromptu meeting to find out what it would take to get me to stay. I told her I would need at least as much as the offer which was 40% more than my current salary. Her response was "do you think you are worth that?". I told her the other company thought so or they wouldn't have made the offer. Needless to say I didn't stay.
I wouldn't even call that mean so much as incompetent and desperate.
I'd maybe try to explain a little that my salary is actually set through a competitive process of interviewing so it's not a number I personally have to have believe in or not, and then maybe touch on why her comments smell of desperation and why that's not a strong negotiating position.