Just to add my opinion and nothing more,
In low range with out CDL locked and spat the CDL to pieces.
Heard the bang and stopped, went to drive again and had no drive at all as no CDL.
He would have then in a panic hit the brakes as hard as he could which slides the fender sideways and the rest is history.
Expensive lesson for such little effort no matter what happened, either not go up that hill (that even if it were steep, I would easilly drive it in my Disco, it's not even rutted that bad) or Lock the CDL (READ OPERATORS MANUAL) and drive it.
Could be like a mate of mine that thinks hes a hero by driving as much as he can in 2 wheel drive in his lux.
Problem is that when he gets stuck he has to get out and dig out his hubs to lock them in, I find it quite funny on occasion.

