EIE involving you
I've found something similar with my EIE roommate - when we do something together, he usually pretends that only I did it and he wasn't involved. I've called him on this, and apparently he'll try to be honest about who did what in the future. He's called for a collectivist attitude in general, which I'm fine with, but he keeps "going the extra mile" and pretending that I'm better than him.
EDIT: He only gives me credit after it turns out well, so this isn't a case of trying to pass on blame.
"Come to think of it, there are already a million monkeys on a million typewriters, and the Usenet is NOTHING like Shakespeare!"
- Blair Houghton