It's really hard to judge college defense to NBA defense. A lot of the stars, like an Okafor, have to be extremely weary of foul trouble and often play worse defense because of it. A team like UK doesn't worry about this as much since they have so much depth.
Yep, I don't think it will affect his current draft stock, unless his team reaches the Elite Eight and he still coasts/is incapable of deterring anyone from scoring.