I'm playing a lazy sim recently, so I'm familiar. Don't look at them a second, and they sleep on a chair.
It's not a passing out in the tub, there's a specific "action icon" for passing out, and the bath one says "falling asleep in the tub", and it doesn't count on the "pass out" counter. I'm about certain that Sims with 0 energy will get out of the tub and pass outside of it.