Originally Posted by when am i?
Well for some people to have gone to a different timeline on 815,there would have had to have been a flash,but we did not see one.Maybe they didn't show it.
If Christian went to a different timeline,then how come he was back at the same time as Jack and co?
Maybe he went through time-travelling flashes that weren't shown.
I don't think that's necessarily true; in 'Follow the Leader', after Richard gave past-Locke the compass, past-Locke vanished. There was no flash.
I'm not sure what you mean by Christian being "back in the same time" as Jack and co. If the Jack and Sayid and everyone else in 1977 decided to stay on the beach until 2004, and if nothing happened to them, their 2004 selves would run into them once they'd crashed. Because they aren't there, it means that either they really did die as Richard said, they're hiding somewhere, or they were transported by a flash to a different time.
I don't however believe that anyone on 815 was flashed to a different time, and don't see how that would effect whether Christian is dead.