When Sawyer jumps in the water to retrieve the raft's rudder, Jin drops the sail. When Sawyer is pulled out of the water, the sail is still raised.
Sayid says that they are losing the light, yet his and Charlie's shadows indicate that the time is close to noon.
Arzt is handling a stick of dynamite. He begins wrapping a muddy shirt around one end of the stick and in the next shot he is starting at the opposite end.
In Michael's airport flashback, Walt is seen playing a Game Boy Advance SP. Later, Walt approaches his father and says he "needs new batteries," however the model of Game Boy he is playing runs off of an internal, rechargeable battery.
Arzt claims that the inventor of nitroglycerine got his face blown away, but Ascanio Sobrero actually died of old age.
The skeletons in the Black Rock are still articulated in a sitting position, and some still have their arms in the manacles. In reality, they would be a pile of bones, given the connective tissue that holds the joints together has rotted away. It is also more than likely that local animals would have fed on the bodies, scattering the flesh and bones around the ship and locality.
After Sawyer dives into the water to save the raft's rudder, he makes his way back on to the raft and collapses onto his back. The raft is supposedly 15 miles out from the shore but when Sawyer is shown in aerial shot, the seabed can clearly be seen.
During Michael's airport flashback, Walt is playing a Game Boy Advance SP, yet the sound effects of the Atari 2600 port of Pac-Man can be heard. However, the game he plays is obviously not the familiar maze game that is Pac-Man.
During Jin's flashback, he meets one of his father-in-law's assistants, and the voice of the European associate speaking in Korean to Jin is dubbed; his mouth moved before the voice came through.
During Michael's flashback of the airport, a close-up shows him talking to his mother on the phone and then pauses for her reply. When it cuts to a distant shot of Michael, his mouth is moving but nothing is heard. It cuts back to the close up, the pause ends and he answers.
After Sawyer goes overboard and is pulled back by Michael and Jin with a rope tied around the rudder - right after Michael says "You just saved our ass man", behind Sawyer and Michael a small boat is visible (very close-by) for a second.