Very interesting. I believe that it is probably stress fractures somewhere on the train. That train gets jostled around so much, with its terrible tracking, that stress fractures have got to occur.
I think the coffin has been nailed on Son of Beast. With its high operating costs, low enjoyment factor, and finally this accident, they'll just shut it down.
Please keep in mind that e-stops can only occur in brake sections, not just anywhere on the track. The trains themselves do not have any brakes on them, so they cannot stop themselves.