Interesting how when some are removed from life support, they recover. Perhaps the body healed itself but was letting the machines continue to do the work. It may be that when taken off the machines, the body is forced to work on it’s own. Could also be that the patients hear and process the discussion of killing them which makes them fight to come back.
I remember a theory about the temperature of the ar they breathe from life support machines might be keeping them in a coma longer.