The final shots of the shattered airliner were apparently put in by ABC (not the show's producers) for, erm, nostalgic reasons, causing consternation amongst fans who thought this meant the entire show was a dream. ABC have apologised and admitted that this was a mistake.

Huzzah! Given ABC's amazing ability to put out rubbish trailers promising more than was ever delivered and to spend the first three seasons moving the show all over the timeslot for no real reason, it's almost traditional that they manage to find some way of ballsing up the finale!