I agree that Terri never would have recovered and most likely (to state one way or the other is simple conjecture) didn't not have remaining mental faculties. Still, why was dehydration used as means of death? I found it to be inhumane and something that just never be done to an animal let alone a human being. They should have just given her morphine.
Once the decision is made, I agree that a faster method could be explored. But Terri's death was painless.