It's highly likely that the QA guy is looking for you to do his job. He's read a few articles in the various trade mags about unit tests, and like others have pointed out, he's trying to make you look bad.
I wouldn't mess with him, head on, but instead, I'd document 20 or so unit tests and send them to him. And by document, I mean press "///" and let .NET do the documentation for you. Fill it out in intricate detail with only the most obvious of comments. Things like:
i++; // Add 1 to i
Be sure to send them back, (cc your PM) and ask him if that is the level and kind of documentation he is looking for.
Then, sleep with his wife.
I was thinking about that (the part about writing 20 or so unit tests and sending the .NET documentation ), but that would involve getting IT requests for intalling NUnit or some other harness, etc.... AFter I talk to my PM I'll see if they want real unit tests or not.