Continuity mistake: In the first shot of Locke sitting in the wheelchair, in the airport lounge, he sits alone directly in front of the long rows of chairs. However, in the next overhead shot, the airline steward is at Locke's side as he sits near the large windows, nowhere near the chairs.
Continuity mistake: In the Oceanic Int'l departure lounge, Locke sits in his wheelchair near the large window, with the doomed plane in the distance. The attendant's desk is on the left, but the black lounge chairs, which are normally situated toward the center of the lounge, are gone in this shot; the chairs at the end of each row should be visible at this angle. These chairs are also seen when Hurley crashes the scooter into them.
Continuity mistake: When Michael sits with Walt at the airport, Michael says, "If you're worried about Vincent," and the newspaper in his hands is folded and held straight up with the blue Oceanic envelope. Yet, when he says, "Dogs fly in the luggage compartment all the time," the newspaper is sideways and there is no blue envelope.
Continuity mistake: When Kate and Sawyer begin their swim, Kate is not wearing a bracelet on either wrist, as she heads into the water. In a few following shots, including when Sawyer goes to "See what they got on em," Kate wears a bracelet on her right wrist, but when they head down to retrieve the case, the bracelet is gone as she pulls on the case. After Sawyer frees the case, in Kate's close-up the bracelet reappears, but now it's on her left wrist, yet when they reach the surface the bracelet's on her right wrist. Whew!
Factual error: Naomi Doret, the woman who parachuted onto the island, is explaining about the outside world finding the wreckage of flight 815 "off the coast of Bali, in an ocean trench 4 miles deep". The problem with that statement is that Bali is nowhere near the Pacific Ocean, it's in the Indian Ocean. Oceanic flight 815 was a direct flight from Sydney, Australia to Los Angeles, US. That flight wouldn't go anywhere near the Indian Ocean or Bali.
Plot hole: Sawyer pulls the bullet out with his bare hands, we are led to believe, through the cut the bullet made. When you are shot, the flesh immediately seals up, meaning you would need a knife or something like that to get it out. Sawyer only had the gun, as he could not have hidden the knife AND the gun.
Continuity mistake: When Jack is packing water bottles in to the sack and Locke says "I think one of us should stay and help Charlie salvage the wreckage", you see Jack putting a bottle in to the sack. His hands are now empty, but when it cuts he suddenly has a new bottle in his hand which he puts in to the sack.