Rolf,
I would rather be hit by a bunch of flying cushions, and maybe a teakettle, below deck than be thrown off the boat topsides.

There would be plenty of air in there to survive for a long time, and the boat is not going to sink for a long time, if at all. And you want to be COMFORTABLE AND DRY, too?

I don't know whether new cruising multihulls are made with an escape hatch on the bottom. I do know that if they had all been buttoned up inside the boat when it rolled, they probably would all still be alive. It wasn't very long before the boat was found.

The big point is that in bad conditions they should have at the very least been tethered to jack lines.

And a problem is that people tend to be complacent with a multihull because it SEEMS so stable. So they do not always take the precautions they would take on a monohull.