PP, I expect the accident investigation will confirm your analysis. Ski-jump is a good analogy. Had the gradient up the berm really been that of a ski-jump the aircraft might have actually become airborne without breaking its back. Which is what one suspects happened when the main gear hit the berm. The centre of the fuselage would have been projected upwards and the after half of it would have hit the berm at an even greater angle than the aoa during the last few hundred metres of the takeoff run. Thus knocking the heavier tail section off and bouncing the aircraft over the trees and the road, rear hull flapping and engines still at full power, into the quarry beyond.
The whole thing is one of those nightmare scenarios where cause, sequence and outcome seem inevitable. Maybe, because of its slightly higher profile than accidents in Nigeria, Equador or other places that don't attract so much attention, it will nudge operators, regulators and airport authorities.