Imagine if Karana hadn't gone back for Ramo. It's likely he still would have ended up dead (if anything, he probably would have died sooner given that he wouldn't have had Karana's moderating influence to keep him out of trouble), and given how long it took them to get back to the island for Karana, it's likely there would be nothing left of Ramo's body by the time anyone returned. Instead of successfully retrieving a living person, the would-be rescuers would presumably arrive to find no trace of him, and his family would be forever left with unanswered questions.
