Continuity mistake: The little projector in the Odyssey book only lights off at the end of the briefing video, but in the following frame when Ethan closes the book it's already back inside it. (00:04:50)
Continuity mistake: During the rescue of the White Widow, she stains her clothes with blood, from the left bust to the side, in the next scene, the stain is no longer on her bust, only on the abdomen and very small. (00:40:05 - 00:40:28)
Continuity mistake: In the bike chase, Ethan has side mirrors in all but one scene where he is surrounded by police coming from all corners. The bike's mirrors are missing then. (00:59:10)
Continuity mistake: When Benji is sitting back to back with Soloman Lane to duplicate Lane's face, his jacket is green, then they cut to face Luther asking whether Benji is OK, when they cut back, Benji's jacket is the same brownish color of Lane's jacket. Later, Benji wears the green hued jacket again when talking to Luther and Elsa. (01:23:30)
Continuity mistake: As Ethan climbs out of the hatch (on top of the Tate Modern) he leaves it open and runs to catch the helicopter opposite him. However, he misses it and is left alone on top of the Tate facing the helicopter. As the camera pans around the hatch is now to the right of him and closed. (01:51:10 - 01:51:35)
Continuity mistake: When Ethan is thrown from the helicopter, he lands with a straight black strap attached to his left wrist. When he comes to a few seconds later, the strap is now doubled up and he's gripping it, it's not attached to him. (02:03:30 - 02:04:30)
Continuity mistake: During the getaway in the 4-door olive-green BMW, in one shot, the driver's headrest is bent forward; in the next shot, it is shown back in the straight-up position.
Continuity mistake: The scenes in London show the Thames river at low tide in some shots and at high tide in others.
Continuity mistake: During the first chase in Paris, the streets are dry, then suddenly wet.
Continuity mistake: The fight scene in the nightclub toilet between Hunt, Walker and who we believe is Lark is brutal. Both Hunt and Walker take several blows to the head and face, but when it is over there isn't a mark on either of them.
Continuity mistake: At the start of the truck chase the road is completely dry and it's sunny, as they go over the bridge the road is completely wet and it's overcast, then the road is dry and it's sunny again.
Continuity mistake: When the truck gets knocked into the river it is almost submerged by the time Ethan reverses the truck. Cut to part of the truck chase and then back to the river - the truck is sinking again and the driver and passenger are getting out. The truck is also at a different angle to when it first went in.
Continuity mistake: During the BMW/Bike chase in Paris, Ethan crashes through some parked motorbikes and drives away, the rear window on the passenger side is completely open. Before and after this scene the window is shut.
Continuity mistake: When Hunt reverses the truck into the street and drives off, dumping the bad guys onto the road, the doors are swinging about as they should be, but for the rest of the chase they are shut and latched so they can't come open again. This has to be done manually.
Continuity mistake: When Hunt and Walker extract Lane from an armoured convoy by alternate means, right after they push the truck containing Lane into the water, one of the police in the convoy tries to shoot Hunt and Walker, leaving 3 bullet holes in the front windshield of the truck. Afterwards, the bullet holes keep disappearing and reappearing when Hunt and Walker escape with the truck across Paris. The most obvious occurrence when the bullet holes disappear is when Hunt and Walker kick the front windshield of the truck to flee with a motorcycle after it gets stuck between buildings.
Continuity mistake: When Ethan is chasing Walker up the brick tower, the hatch to the roof is in the middle of the tower when seen from the inside. However, in the exterior shot, we see that there is no hatch where Ethan is pretending to be exiting. Later we see the exit to the roof is on the side of the building.
Continuity mistake: The amount of blood on Hunt's face changes during the last fight against Walker.
Answer: They are in France. The French word for police is "police."