There is one thing missing from this thread that people haven't taken into account. Jack was super upset at the death. What would have happened between being on the island and getting off that would suddenly make Jack so upset about Jacob? Another thing people keep pointing out which I think may have relavence is that the coffin seemed rather small. But I can't think of a dude from the show who is small aside from maybe Ben and Walt but we now know that Ben is still alive and I don't think its Walt. So now I am confused...