Offhand, I can't remember God ever removing a feeding tube in order to dehydrate the patient to death. Quite the contrary, God said that if you deny water and food to the least of his children, you are denying Him. If you want to see what comes next, check out Matthew 25:41.
Not only that, but is Crist so vain to think that if God had actually wanted to call Terri home, a feeding tube would have stopped Him?