Revealing mistake: When Goodwin and Ana Lucia sits down to have a break and Goodwin hands over some fruit to Ana, she says "Where do you think they got it? I mean they're not even wearing shoes", directing to the knife. If you watch in the background you can see a car driving.
Continuity mistake: When Claire is holding Aaron talking to Locke, she says "I can't believe he is still sleeping" and they show him sleeping. She then asks Locke if he wants to hold him and then hands Aaron to Locke. His eyes are wide open. Then you see Locke obviously holding a doll in the next shot and they are talking about him still being asleep. Locke then hands Aaron to Charlie and the eyes are again wide open and they are still talking about him being asleep.
Continuity mistake: In Episode 2-23 Live Together, Die Alone When Mr Eko runs out of the hatch when John and Desmond are faking a lock down, you see Eko put his club in his belt right in the front of his pants. In the next scene as he passes out of the door the club is gone and then when he runs back to the door as it is closing he is holding it in his hand as he drops it and it falls under the door.
Revealing mistake: After Sawyer has been shot with the syringe thing (I'm not sure if Kate had been shot yet) Jack fires his gun five or six times into the jungle. The last few times he fires it there is no flash or any indication that the gun has been fired.
Continuity mistake: In this episode Jack works on an old crippled man to try and perform another "miracle." Remember, this is supposed to be in Jack's past. When he's looking at the x-rays in the beginning, take a look at the dates on them. They're November 16, 2005. In the last episode of season 2, Desmond says that the plane crashed in September 2004.
Continuity mistake: In the scene where Sun surprisingly sees Michael running out from the jungle, Sun turns and faces Michael, who is on her right. In the close-up shot followed Sun is found facing to her left. It then changes back to normal in the next shot.
Factual error: The version of Brixton underground station is very lazily reproduced: the 'U' and 'D' of the 'UNDERGROUND' roundel have been the same size as the rest of the word since before Brixton station was built; the white circle is not part of the roundel; the station appears to be accessed through a plate-glass window; there is no reason for a black cab to be parked at the side of the road; also, the cars are all parked along the right-hand side of the road, which they would never be in the UK.
Continuity mistake: When Jack and Ana-Lucia are talking on the rocks by the beach at the end of the episode, Ana-Lucia's hair is pulled back and is completely off her face. However, in two of her close-ups, there are two small forelocks loose in the wind near her temples, which are not present in any other shots during this scene.
Revealing mistake: As several camera angles show, Sawyer's makeshift stretcher was made by drilling multiple holes in the upper frame struts, through which was threaded rope made from dried roots or vines. The cast who supposedly constructed it were not carrying power drills among their primitive implements.
Continuity mistake: Ana-Lucia says that she never saw Nathan during the two hours the plane was in the air, which Cindy the flight-attendant agrees with, saying that she has a photographic memory for passengers. But the plane was actually in the air for eight hours before the crash, as revealed in the pilot, so, not only should Cindy remember him after that long, but they all should be able to tell the difference between two and eight hours.