When Sawyer is seated on the beach and Jack approaches him about his headaches, Sawyer mentions that his uncle had a brain tumor. The camera angle changes from Jack's perspective to Sawyer's perspective, back and forth, about 5 or 6 times. Jack has on a leather backpack in some of these shots and sometimes has a sporty grey backpack. You can see the difference in the width of the shoulder straps!
When Locke first meets his biological father, Cooper puts ice into both of their scotch glasses, but when he hands Locke his glass and they drink, neither glass has ice in it.
Boone falls forward with the plane from a cliff while standing in the front, but Locke finds him back in the middle of the craft.
When Locke is shown in his flashback setting up the board game Mouse Trap at Walmart, a boy comes up to see the game. Locke goes over to talk to a woman and tells the boy to turn the crank on the game. We see the first half of the trap go off, the scene cuts to the conversation Locke is having and we hear the noises of the Mouse Trap game going off until the last part when the cage drops, but then the sounds of the trap are looped or new sounds are played to make the trap seem longer than it actually is. Then, before the flashback ends, it cuts back to the board game showing the last half of the trap going off, which would have really been finished after a few seconds of Locke's conversation with the old lady.
Right before Locke finds the body of the priest, when Locke and Boone are looking for the plane, Locke takes out his compass. But he had previously given his compass to Sayid, saying that he didn't need it anymore. However, it's a different compass.
Locke's mother describes him as being "immaculately conceived" because he has no father. However, the doctrine of immaculate conception does not refer to the virgin birth of Jesus (when Mary conceived Jesus without the aid of Joseph), but to the birth of Mary, because Mary herself was free from original sin when she was conceived. "Immaculate" literally means "without stain", which in Christianity refers to the original or ancestral sin with which all people are born.