Exactly correct.
In your #590 you cited a couple of instances of 'past treatment' which you felt were important. "* [failure to] order regular dental care (her teeth are presently rotting due to a lack thereof). * [failure to] have therapies aimed at improving her quality of life, such as restoring her ability to speak and swallow. * [failure to] have the broken bones in her body properly mended (I'm not a doctor and don't know if this is possible. BTW how did she get the broken bones to begin with?)"
Standing alone, there is no evidence that any of these explain Terry's present inability to feed herself. Isn't the whole problem here a dispute as to whether all the 'therapies' in the world could restore her ability to speak and swallow?
Look, I realize it is hard to say that someone should be allowed to die when their own condition prevents them from living. But physical life is not the ultimate value. If Terry knows Christ, she will live forever -- and she won't need a feeding tube.
Where would this stop? Suppose all she needed to survive (beyond the feeding tube] was a 'little' heart/lung machine? Suppose the machine cost $1 million? Suppose $1.95?
Suppose there were 1 chance in 100 she could survive for 10 years in that condition, would you want to overrule the (hypothetically honest and caring) husband? How about 1 chance in a million?
You can't write such a law and you really don't want to. Let her go home.