From the forum, discuss Battlefield 3:

A lot of bugs, something they missed

Even funny things:
In one of the first missions it was necessary for one of the partners to open the door, and the three run through the door as nothing happened.)
I think they all came.
but here one of them again through the two returns and typically apologizes brother we forgot that you can't do so, knocks the door off the leg and we have fun running on :)