No, it's much simpler. It's to do with cooling and metabolisms slowing down. Like hibernating. Or deep freezing.They are also able to revive people who have fallen through the ice after a seemingly impossible length of time. Apparently the very low temp shuts down the metabolism to the point where the air in the lungs is sufficient to sustain the person until rescue arrives.
Air in the lungs have nothing to do with it. If they've drowned, lungs are full of water.
It's age related, young organisms can put up with a cardiac arrest and anoxia without damage a lot longer.
The problem comes with warming them up.
Pretty lengthy cardiac arrests in young people or children can be retrieved without sequels. Sometimes.
Paul