[user104658]

As far as I understand it, the treatment can only halt the illness, it can't reverse any damage already done. Basically he might have survived but it would have been with severe brain damage and potentially in pain. I've also read that the actual doctors running the treatment in the US had some reservations with his specific case and the ethics of going ahead with treatment.

Its a complicated area really. You're balancing the merits of "life at any cost" vs life with any sort of quality. In this case, I fully believe that his doctors have his best interests in mind when denying this treatment.