Thanks for replying. The latter. So I've played the game a zillion time and for one reason or another (usually RP) I've let Lae'zel or Shadowheart die on the Nautiloid, and when I find them on the beach, they're dead.
Since Patch 6 (or hotfixes) they can completely die on the Nautiloid but they're either (in Shadowheart's case) lying there unconscious, or (in Lae'zels) a prisoner.
Normally they'd be a corpse on the beach. Now they die on the ship and are just fine.