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 Mr. Eko heads out to the water to pick up the dead bodies you see all the bodies floating face down. When it cuts there is a close up of a body that suddenly floats face up.
Continuity mistake: When Ana-Lucia gives mouth to mouth on the little girl, the girls left side of the face is partially covered in sand. When it cuts her face is full of sand.
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.
Continuity mistake: In season 2, episode 5, Jin and Mr. Eko are searching for Michael. Jin gets attacked by a boar and rolls down a hill to find the corpse of Goodwin. In this scene they are in the middle of the jungle. Now two episodes later, when Ana-Lucia confronts Goodwin they are on top of a mountain without trees surrounding them. This is confirmed in Juliet's flashbacks in later seasons when Ben takes her to see Goodwin's body.
Answer: He was eating a peice of an orange with the skin still on.
XIII