Feature.
Since sometime in AH2, HTC introduced a sort of a 'pilot fatigue'. (Actually, it was in AH1 too, IIRC, but it was unsiginificant)
So, your pilot may tolerate frequent tunnel visions and maybe small slips into total blackout, but when you pull too hard into too much Gs, your pilot faints for a moment, and totally blacks out until regains consciousness.