This has been bugging me because the writers never really explained anything about it. Jin clearly should have been obliterated by the freighter explosion, but somehow was alive floating on some peices to be found later by Ruseau (spelling?)and her crew. Is the only explaination that the island didn't want him dead yet, so it was able to prevent his body from being burned/drowned/etc? Seems like kind of a cop out writing-wise, which doesn't usually happen in LOST.