Whatever the Case May Be - S1-E12
Revealing mistake: At the bank, when Kate shoots her accomplice in the leg, the small square indentation on the pants, around the bullet hole, where the stunt device is located, is rather obvious. (00:33:20)
Exodus (2) - S1-E24
Revealing mistake: After Charlie receives a large gash on his forehead, from Danielle's trap, Sayid tries to seal it. When Sayid pours gunpowder in the cut, he leaves a large thick trail beside Charlie's eye and on his cheek, which he does not wipe away. There is a tight close-up of Sayid igniting the gunpowder with the flame. The gunpowder beside his eye and on his cheek should have seared his skin, but it does not. The only severe wound Charlie has later is the closed charred wound on his forehead, and though he does wipe his face back at the cave, the skin on his cheek and beside his eye are fine. (00:51:25)
Exodus (1) - S1-E23
Revealing mistake: In the scene just after Sawyer is mounting the radar on the mast of the shop, Sayid hands Michael a flare gun. He opens it to show that there is just 1 shot left. If you look closely the flare gun shell has already been fired (notice the center fire pin is indented). (00:34:30)
Exodus (1) - S1-E23
Revealing mistake: When we see Jack and Co on the way to Black Rock, walking along some rocks just as Locke notices the scratches on Danielle's arm, Jack's tattoo is not visible on his left shoulder, revealing a flipped shot. (00:24:30)
Exodus (1) - S1-E23
Revealing mistake: When Kate is hit to the ground by the marshal, her handcuffs are extremely loose enabling her to remove her hands with ease. (00:21:50)
House of the Rising Sun - S1-E6
Revealing mistake: When Sawyer pulls Michael up out of the water it's clear to see it's a stunt double and their hair is a lot longer than Michael's. (00:06:35)
House of the Rising Sun - S1-E6
Revealing mistake: When Charlie is stood on the bee hive, all the bees are clearly CGI. (00:10:00)
Answer: He was eating a peice of an orange with the skin still on.
XIII