The car chase begins in a parking lot, where no cars are hit. But immediately after leaving the parking lot and taking to the streets, the red car shows signs of damage on the front and sides. So, some of the car chase scenes are shown out of sequence.
During the chase at the end of the film, Inspector Zacharia stops a taxi in order to chase Azad. The road is wet because it is raining. But in the next scene, where Azad is hanging from the bus, the road is completely dry.
When Belmondo arrives at the El Dorado club, he is wearing a tan trench coat. As he's watching the show, he's suddenly wearing the brown leather jacket he wears for the rest of the film.
Right after the burglars spot Abel Zacharia following them, they stop to separate. But Abel Zacharia stops his car before the burglars do, showing that it was a prearranged stopping point that he mistakenly reached before them, which was necessary because of the camera angle and the particular way Abel Zacharia's car was framed through some shipyard materials.
Just before the car chase begins, Abel Zacharia is following the burglars around the docks. They act like they don't see him until they find their ship dry-docked, but in every scene he is the only car around besides them, is clearly very close to them watching them, and follows them closely. It would take a blind person to not notice they were being followed.
The team are very professional, they spent two month to prepare the buglar, spent a lot of money in the suitcase for cracking the safe and simply let the car in front of the house with the gate open...