Revealing mistake: When Tom Cruise and Bill Nighy go to see Tom Wilkinson for the first time there are 2 reverse shots from behind Tom and Bill - if you look you can see Tom's hand is still there - it has been digitally removed in all other shots.
Revealing mistake: During the intro sequence where we see a UAV deploying a guided missile, the word "INERT" is seen stenciled on the side of the missile.
Revealing mistake: When Ricky and Brandon are on the ferry, the camera shows Ricky reaching down to grab Brandon's butt and then it cuts to Chance and Eddie. If you look closely, Ricky and Brandon are re-creating the scene they just performed.
Revealing mistake: When Eli's guardian is disposing of the body of the man she killed in the underpass, we can see that the 'body' is a very poor quality dummy, the hands especially are very plastic-looking.
Revealing mistake: Lighting screens are constantly reflected in McQuarry's glasses all through the film.
Revealing mistake: In the explosion of the opening scene it is apparent that cut scenes have been shot with several hours time difference because the sun has moved. This is best visible in the reflection of sun in the helmet and shadows of the vehicles in the background.
Revealing mistake: After Mahogany is thrown off the train, as the train brakes and begins to stop, there is a shot of one of Mahogany's hung victims and you can see the whole body vibrate like rubber, which it was made out of. (01:21:47)
Revealing mistake: In the opening scene, when Van Damme kicks an opponent onto the boot of a London Taxi Cab, you can see the dent from previous takes.
Revealing mistake: At the beginning of the funeral for the girl who died in the motorcycle accident, the supposed corpse can be seen breathing. (01:14:35)