here's a few things I noticed:
Rusian UAV has some strange camera. You can't use mouse for free look. Camera is set to aim at the area below the UAV then it aims for like 5 seconds to the right and then it aims again below the UAV.
Another thing is that russian UAV really strangely "swings" while moving. I'm no expert about these things, but I think that normaly it wouldn't even be possible to move this way.
NV Goggles I noticed that while using NV you are able to see shadows. Even when it's clouded. I don't know how NV actually works, but this seems to me strange.
While playing as russian guy and got hit I noticed that my character sometimes says "Fuck that hurt" or "My fucking leg". The thing is that russians (as well as Chernarussians) say this in english and not in their native language. It's actually no big deal but it just sounds strange.
And the same thing with SecOps module. When russians call for arta fire then the guy on the other side of the line is american - then it looks like that russians are asking americans to bombard them selves.
SVD Dragunov and KSVD (don't remember name of thah gun - just that russian long range sniper rifle) have completely the same sound. But I've never used those guns (or any gun at all) so maybe they do sound the same, thou it seems very unlikely. But again - no big deal.
And last thing I noticed: When you carry a wounded team mate and you stop moving then the character stops in a really strange position. When you look from a side it looks like the character stands just on one leg and the other leg is almost lifted or in "ready-to-go" position (I don't know how to describe it - just try it on your own and I believe you'll understand what I'm talking about)
Most of these bugs are not essential, but perfection is in details :)