Is this character a mary-sue?

It's hard to tell, even from the detailed RP you have here, whether the other person is indeed trying to one-up your character. I think that if you're very worried about it, or if it really bothers you, you should (respectfully) take it up with the other RP'er. It could be just a misunderstanding or accident; then again, it could be that the other person is truly trying to upstage your character. As I said, it's hard for me to say from just this small piece of the RP.