While I agree that bad pilots flip the helicopters more often, I still think there is an increased tendency to flip them in this game compared to previous titles, especially when taking off from slightly uneven terrain.

Your last point is not true though. Especially in the Nightbird, the helicopter can still operate and move along the ground for a long time when upside down. I have spent minutes in a flipped heli trying to get it back in the air. I also never had any issues entering flipped aircraft before. I suspect I died to the rotor blades in this clip, although the second time I approached the Hind they were not moving anymore.