No he doesn't. He calls you some name that starts with a Q and means Vanquisher. I haven't met anyone who recognizes me as anything other than a Dawnguard.
That is lame. I thought that there would be a line for example like this one:
Harkon: You want to destroy me? A mortal, huh!
Dovahkiin: You really do not know who you are messing with.
Well not exactly these lines.,but You get the big picture.