First off, Wow!
I dont think they are running a parrael universe thing. What I think they are doing is showing two moments. One is what happen after the bomb went off- they were thrown into the future.
the LAX crew is what happens toward the end of the show. The island is sunked to the bottom of the ocean -most likely between Jocob and Mr.Black using the losties.The big question then is if so, did the two die or is one of them -esp Mr.Black- one of them finally off the island.