Revealing mistake: On their way back to the hatch with the dynamite, Kate, Jack and Hurley run from the "monster" but Locke runs toward it. When he lands on his back the shot cuts away to the "Lost" logo floating onscreen. When it cuts back to Locke, in this shot the bruise is over his right eye, instead of his left. The shot is flipped.
Revealing mistake: Locke is chased and grabbed by the "monster," and is subsequently pulled through the jungle on his stomach. Just after Jack jumps and grabs him, Terry O'Quinn's right pant leg comes up and his black shin pad is clearly visible, as he is being dragged.
Revealing mistake: When Shannon carries and drags the luggage (some of Boone's) she breaks down and Sayid speaks to her. When he says, "It won't be too much if I carry it for you," he strokes her cheek with his left hand - note the watch. After he says, "I have a hike to lead," in the next wideshot he's still holding her face with his "left" hand. But, note the lack of watch, and her large suitcase is now backwards. They flipped the shot so his right hand would appear to be his left, to keep hand continuity, but it doesn't work.
Revealing mistake: After Sawyer jumps into the water to retrieve the rudder, Michael tosses him the rope then shouts, "Tie it around the rudder and we'll pull you in." Three shots later, in Sawyer's close-ups, mountains are visible at the right of the screen, whereas in the previous and following consecutive shots they are surrounded only by water at this point in time.
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.