Something that currently plagues ARMA 3 is that the door gunner on the Ghosthawk has no method of freelook at all. After crewing a Ghosthawk in a session recently I realized how hard it is to be a Crew Chief without the ability to freelook.
As my view was fixed on the gun I was unable to tell the pilot when all units were out and the aircraft was clear to take off. It also means that when the aircraft is just on flight somewhere the camera view for the door gunner is very boring and he cannot look around the aircraft.
It almost seems like a cop out and that there are really low detail parts near the gunner or as if the idea of the gunner being able to see him not holding the M134 is bad. If either of those are the case then it really does not matter as it really detracts away from the experience.