Goofs

When Desmond unties Minkowski, there is a two second shot in which it's quite clear that Minkowski doesn't have blood on his face. Seconds before and after that, he has blood that came out of his nose.

The number for Penny that Desmond retrieves is before the London area code switch over. When he dials it in the present, it would have changed over.

The army trucks shown are not standard British Army trucks.

When Desmond is speaking with Mr. Widmore in the restroom, Widmore washes his hands by grabbing a towel from a tray to the right of the sink. He leaves the water running and leaves the restroom. Desmond then flashes back to the boat. When Desmond flashes back to the restroom, it looks like the tray is to the left of the sink that was left on by Mr. Widmore in the previous scene.

In fact, the shot has simply widened, showing towels next to each sink in the restroom. The towel used by Mr Widmore, as well as the tray he got it from, is still to the right of the sink as he left it.

When Sayid, Minkowski and Desmond enter the boat's communication room, a lot of the radio equipment seen is actually more or less professional audio equipment. There are several graphic equalizers that serve no real purpose in such a facility, and the device Sayid rips out of the rack is a club mixer used by DJs.

The auctioneer says that the ship Black Rock was lost at sea on its maiden voyage in 1845. The Black Rock has been shown to have carried dynamite, which was invented in 1866.

The location used for the University of Oxford looks nothing like the real place.

In the British army, a sergeant would not be addressed as "sir." He would be called "sergeant" or "sar'nt."

Daniel tells Desmond he'd do an autopsy on the rat later. The autopsy of an animal is called a necropsy.