Factual error: The scene where Nightfox steals the Faberge Egg is all wrong. A laser security system must have a photoelectric receptor at the other side to detect if somebody pass between the two devices. As shown in the film, the laser beams points everywhere, so the system can't work and somebody could cross a beam without starting the alarm. Even if it was some weird system based on measuring distance it wouldn't work - if the laser hits the floor at an angle it won't bounce back to the source, it will reflect towards the ceiling.

Visible crew/equipment: in the scene where Ocean tells the Nightfox about the fake Fabrege, there's a shot of the Nord Train. in the shot where we see the left side of the train, watch its window and you will be able to see a camera and a cameraman reflected.

Deliberate "mistake": Laser beams are normally not visible, except for a small dot where they hit a surface. Even if made visible, using smoke or dust or special glasses, they are thin as threads. Obviously something more visual was needed for Toulour's dance act, hence the thick beams of light.

Visible crew/equipment: In the first scene, as Rusty walks through the house, you can see the silhouette of a crew member crouched down at the far right of the screen.

Continuity: In the scene towards the end of the movie a man is looking at a check. On the check is written "One hundred and Eighty Nine" so on and so forth millions of dollars. The camera then pans to the numbered cash amount on the right, and it says $198 etc., among other numbers, rather than $189 etc.

Other: The shot when Basher and Linus are practicing the switch is impossible to do in one shot. There are two items on the stand, the Egg and a carriage next to it. There is no way that Linus was able to grab both items (one in each hand) and put the hologram down without it being two shots.

Other: When Bruce Willis enters the hotel room in Rome to see Julia, Matt Damon reacts twice with surprise when he turns around and sees Bruce.

Continuity: Before some of the group is arrested, Brad Pitt is sitting at a restaurant table and 4 cops approach him (2 from the front and 2 from behind). In one shot, the two cops in the front are seen about to sit down, but in the next shot, they are just arriving and aren't even close to the chair.

Visible crew/equipment: In the scene of Matsui's interrogation, you see Catherine Zeta-Jones leave the "pre-interrogation room", walk behind a glass through a corridor and finally enter the interrogation room; in the last seconds of her walk, you can see the shadow of the moving camera on the two-way mirror.