i was just thinking...
i could be totally off here, or if anyone else said something about it then i apologize, buuut
you know how in the pilot episode, Jack was pretty far away from the beach when they crashed? and everything around him seemed like he wasn't thrown over there or anything... and of course the bottle wasn't broken...
And then the second time when they went on the plane to go back, everyone that has been on the island already "flashed" off of the plane?
could Jack have been on the island before the first crash??