When you are prone, aim down the sights and press Q or E to roll the camera just moves left or right with your hands rotating around it.

Rolling is always a bit disorienting in real life too, but in ArmA3 the issue causes the view to be incredibly stable and you can easily keep a, for example, moving enemy within your sights which gives you an unfair disadvantage versus his view since he's moving.

Movement view and perception however is much more stable than when rolling but in Arma3 it's the opposite.