I figure the shock is what let him do it.
That and it was already mangled good.
I was reading the other day about a similar situation. Farmer gets his arm caught in the machine and was being pulled into it. Then the machine burst into flames, he caught fire while being sucked into the machine.
So, he pulled out his buck knife and cut his arm to free himself. Then extinguished the fire on his body. Walked two miles to the county road an flagged down a car.
Driver of the car was an off duty paramedic.
I think that God didn’t want the guy to die that day.