That is beyond words. You cannot 'save' a snake in that condition (spine ligaments, nerves and most of the connective tissue are completely gone). They did not 'rescue' the snake at all. This animal needs to be put down as quickly as possible, I can't even imagine how much suffering this poor thing is having to bear.
If the rescuer is reading this, PLEASE take this animal to the nearest emergency vet. If you cannot afford it, please PM me, but one way or another, you CANNOT let this go on any longer. Please do the right thing.
~Kat