I've noticed this reported before but it has never been fixed (for me at-least)mostly tested in the mh/ah-9 helicopters when i free look with ALT then let go it sometimes returns to an incorrect position, also if i toggle free look then un-toggle free look it snaps to the original position for a brief second and then returns to the incorrect position, the only solution I've found is to exit the vehicle and then re-enter the vehicle.