Continuity mistake: At the start of the "Nice" scene, De Niro is standing under the big NICE sign with a gold post, but in the following shot he is about two feet away from it. (00:39:50)
Continuity mistake: In their initial hideout discussing the ambush, De Niro repeats several times to Sean Bean "Draw it again" then they have argument and De Niro apprehends Sean Bean. In the shot where De Niro pulls gun out of the back of Sean Bean's trousers, Sean Bean is definitely turned with his back to De Niro, where in the previous and following shot he is facing De Niro. (00:29:30)
Continuity mistake: At the end of the chase in Paris, when the BMW falls off the bridge into the building site, Gregor leaves the car through the back door window. During the chase he sat in the front of the car. He had also fastened his seatbelts, which would have prevented him from falling into the back of the car while it was crashing.
Continuity mistake: When Seamus, Deidre and Gregor are in an apartment just after Seamus comes out of the bathroom after beating up Gregor, he is holding a glass in his left hand after he pours the drink, then in the following shot the glass is now in his right hand. (01:13:20)
Continuity mistake: In the ambush under the bridge, the police car which can be seen across the river is a Peugeot 405, yet by the time it reaches the people at the bridge and chases the Audi it is a much smaller Peugeot 205.
Continuity mistake: During the final chase, if you see Deidre's hair, you will realise that the window was sometimes open and sometimes closed.
Continuity mistake: As Gregor tries to flee on foot through a crowd from Sam and Deirdre, he jumps down several stairs and loses his glasses which spill to the ground, with Sam right behind. Cut to next shot of Gregor running toward the camera with glasses back on, pursued by Sam. (01:07:00)
Continuity mistake: At the end of the main car chase on the bridge Robert De Niro's car skids to a stop and has virtually done a 180 degree turn, but when the other car goes over the edge De Niro's car is sideways.
Continuity mistake: During the final chase the cars enter a tunnel and Jonathan Pryce starts shooting at De Niro's car. To avoid being hit De Niro drives on the outside and starts to overtake a car to use as a shield. The inside shot doesn't show this car, and when the driver gets shot in the arm De Niro's car is somewhat behind it.
Revealing mistake: In the final chase a car gets spun around and hit by a lorry - the car driver is an obvious dummy.
Continuity mistake: When the group are discussing the plan for the ambush, the top line and words on the whiteboard changes, and the arrow changes from being pointed at the bottom of one of the photos to pointing at the top photo. (00:27:35)
Revealing mistake: Obvious studio shot when the BMW starts to flip at the end.
Continuity mistake: When Frank and Deidre are in the car watching the villa and she climbs onto his lap to kiss him while he is in the driver's seat, it's clear that there is no steering wheel in the vehicle.
Continuity mistake: When the BMW exits the final tunnel before it crashes, there is a shot of the windscreen wipers moving up, but in the immediate next shot, they are down.
Continuity mistake: At the beginning, when the group are discussing the plans for the ambush and the driver says, "I'm gonna need an Audi S8," Gregor looks up and stops writing, but in the following shot his head is down and he is still writing. (00:12:05)
Continuity mistake: Just before the Nice chase scene when Deidre gets off the train, she walks to an elevator. If you look to the left of the screen you can see Seamus with a black hat or french beret on, but in the following shot, the hat has disappeared. (00:25:20)
Continuity mistake: Just before they head out to make the deal with the arms dealers, De Niro and Skarsgård are talking at a table, if you look on the table there is a flask and a cup. In the first shot, the cup is on the left of the flask, but on the overhead shot it's on the right of the flask, then it's back on the left. (00:14:00)
Visible crew/equipment: During the scene at the whiteboard where Robert De Niro is asking Sean Bean about the colour of the boathouse at Hereford, the shadow of the boom mic can be seen on Robert's forehead.
Continuity mistake: When the group is going over the Nice ambush, Sam gets up, closes the door and Deidre walks in from the kitchen and sits down. At the door, Larry is taking a sip of his drink, but in the following shot the cup is on its saucer and he is holding it with both hands. (00:31:15)
Other mistake: At the very end of the final chase, Vincent fires his gun and the BMW wheel was slashed. But Vincent aims his gun to a higher position, not to the position of a car wheel.
Chosen answer: It is true that it doesn't affect the plot. However Spence's (Bean's) failure can be contrasted with the professionalism of the main characters. Also it raises the possibility that whoever hired them isn't taking necessary precautions in planning and hiring. Earlier we heard Sam (De Niro) ask Vincent (Reno) if he was "labour or management" which suggests a theme of professional operators getting their hands dirty while their bosses play politics.