Revealing mistake: The scene of rioting in the UK features a load of police officers running through a crowd. All the officers shown are wearing black tunics and custodian helmets worn with chinstraps. This is obviously old stock footage from a protest in the 80's or early 90's as nowadays, (and especially in 2012) the tunic has not been worn as general wear for well over 15 years, and Brit cops are now better equipped for protests with body armour, NATO helmets, flame retardant overalls, etc.martinjfox
Revealing mistake: When the old couple who give Wolverine clothes are first driving towards their house, there is an aerial shot of them driving over a bridge. This is supposed to be set in Canada (drive on the right) but it was filmed in New Zealand (drive on the left). They are driving on the right but the arrow on the road is on the left side.
Revealing mistake: When Holmes is looking at the white mark on Watson's fiance's ring finger in the restaurant, shortly afterwards a blue flashing light goes past the window.
Revealing mistake: Just after the submarine crew see all the whales passing them by, the shot switches back to the helicopter and all the dials on the console. If you look closely, you can see that the image has been flipped as all the words and numbers are the wrong way around. (00:05:20)
Revealing mistake: When the Federation fleet is preparing to warp to Vulcan, you'll see the first ship blast off, but the second ship blasts off out of nowhere. You could argue that the ship was out of sight and below the Enterprise, but the light trail isn't that long. The light trail starts in front of the Enterprise where you should be able to see a star-ship. (00:40:45)
Revealing mistake: Just after the Buick spins around to knock the trailer loose, we see the Buick speeding away backwards alongside the truck. If you look carefully you can see the REAR tires are steering, not the fronts. This car was modified with the body mounted backwards on the chassis because the transmission only has one reverse gear, so to get the speed and handling needed, the car had to be going 'forward' with a 'backward' body. (00:05:30)johnrosa