Whether or not they have a chance at recovery is irrelevant. The fact that they still have some level of awareness is reason enough to not murder them. What was done to Terry was horrendous.
That’s the whole point - Terri was murdered so her husband could marry his girlfriend who wanted Catholic church wedding. He needed to be a widower for that to happen. Not to mention that this really was a test case to “euthanize” a human being who was not terminally ill. Jeb Bush’s shame for not stopping it.