Nothing in writing at all? Plug won't get pulled without a lot of talking and doing all that can be done to get everyone on the pull the plug side.
Too high a risk of lawsuit. From what I have seen.
Can the docs be sure the spouse is not in early dementia or on meds that can be blamed for the pull the plug decision?
It really can end up in court, just to get a plug pulled based just one 'he said to me' word of spouse. Depends how daring the docs are too. Most know even if they win a lawsuit, just getting sued is a lose for them. Big hassle and cost no matter what. So I don't blame them.
"The danger is not that a particular class is unfit to govern: every class is unfit to govern." Lord Acton
The only way to win is to not play...(like global thermal nuclear war).