The loss of a T/R gearbox will also cause a large cg shift and nose-down pitch - the pilot might pull back to correct it and there goes the mast bump?
We lost a Huey in 1981 when a T/R blade separated, the unbalanced gearbox came out, fuselage yaw, pitch and roll, mast bump, rotor separation, blade came through the left cockpit, took off the tailboom, and all in freefall.