Continuity mistake: In the replay of Sawyer meeting up with Jin, Jack, Kate, and Hurley, Sawyer takes his glasses off with his left hand. After the scene cuts to Kate and back, Sawyer is now taking his glasses off with his right hand. Not only that, but during that scene in the previous episode, he only took his glasses off with his right hand. (00:05:20)
Continuity mistake: When Sayid opens the lid of the compass to show Jack, in the close-up, all of Sayid's fingernails are short and trimmed, yet, in previous and following shots (including next episode "Special") some of his fingernails (such as the thumbs) are very long again. This occurs in many other episodes, such as "Exodus 2". (00:24:40)
Other mistake: In the scene with Sawyer and Michael drifting on the pontoon, where Michael is crying, you briefly see a boat with a mast in the background in one shot over Sawyer's right shoulder as he faces the screen, just before he says "Are you all right Mike?". (00:38:10)
Continuity mistake: The blood on Juliette's mask changes drastically between shots. (00:08:15)
Through The Looking Glass (2) - S3-E23
Continuity mistake: When Jack hands the walkie-talkie to Ben, the way he holds it differs between the two angles. In one angle, he is gripping it; in the other, he is holding it on his flat palm. (00:10:30)
Continuity mistake: Just after the title sequence, we see Faraday holding a map in two hands in a close-up, but with one hand and one hand pointing at the map in a longer shot. (00:10:40)
Through The Looking Glass (1) - S3-E22
Continuity mistake: On the plane, Jack's paper is on the armrests until he notices the article; at which point, it is now on the seat next to him. Pay attention to the black marker on the seat. The amount visible changes. (00:02:10)
Continuity mistake: When John is playing chess, we see him make a move, followed by the computer making a move. It's now John's move, but when he makes his move, all the pieces are in different positions. The screen is in shot all the time, and we don't see him make another move explaining the moved pieces. (00:28:00)
Tricia Tanaka is Dead - S3-E10
Continuity mistake: In the VW bus, Charlie says "Victory or death." He has his hand raised in one shot but not in the second angle. (00:34:10)
Continuity mistake: At the very start, when Ecko and Yemi break into the shed, the hand holding the packet of biscuits on Yemi changes between shots. (00:01:30)
Continuity mistake: When John wakes up, the right-hand side of his head is covered in blood, both fresh and dried. When he's looking at Ecko's stick, his head has no blood on it. Fresh or dried. (00:02:40)
Continuity mistake: When Sawyer dumps out the water canteen Juliet tosses him, his hand moves from the top of the base to the bottom, and the angle at which he pours the contents out changes, as well. (00:24:15)
Continuity mistake: When Sayid is talking about moving the boat, Sun's hair is blowing in the wind in one shot but nice and neat in the next. (00:03:00)
Continuity mistake: At the meeting, Jack's dad puts his hand on Jack's shoulder. When the shot changes, his hand has been removed. (00:27:40)
Continuity mistake: When Jack wakes up and hits the communicate button on the wall, his hand is below the box. When the shot changes, his hand is now to the side of the box. (00:06:00)
Live Together, Die Alone, Part 2 - S2-E24
Continuity mistake: When Ecko throws the belt at the wall, the position changes to when Charlie grabs it. (00:05:40)
Live Together, Die Alone, Part 1 - S2-E23
Continuity mistake: When Sayid is praying, his hand positions change between long and close-up shots. (00:40:25)
Live Together, Die Alone, Part 1 - S2-E23
Continuity mistake: When Jack confronts Michael and grabs him by the chest, the way he holds him changes between shots. (00:37:40)
Answer: He was eating a peice of an orange with the skin still on.
XIII