Okay, so in "LAX", the characters find themselves back in 2007. By "The End", when Ajira 316 leaves the island, it is still 2007. John Locke was killed in 2008 (technically the last person to die. So, would it be possible for the survivors to stop Ben from killing John Locke after they get off the island, thus hindering the MiB's abilities to kill Jacob, as well as Sayid, Jin, and Sun? I guess by the same logic, Frank and Kate could visit themselves. Weird.