The music score performed just before the armored truck heist sequence is the same the audience can hear in the film Z, in which there is a fighting sequence between two men on a tricycle carrier platform. The name of the music is Batucada Meurtrière and performed by Michel Colombier. It has never been mentioned anywhere. Only a close watching of those two scenes can notice that.
Jean Gabin himself asked director Lautner to hire Dominique Zardi for the armored truck heist sequence, although Lautner first refused, because Zardi knew how to use a bazooka. The other actor who played the gangster besides Zardi did not how to use this anti tank weapon.
Upon its initial theatrical release in France, the film was classified as being "forbidden to those under 18 years old". This was changed to "forbidden to those under 13 years old" two weeks later after the film was reedited. In February 1990, it was reevaluated as being "suitable for all audiences".
Jean Gabin was very reluctant to get in the Matra coupe; he told director Lautner: " You won't ask me to get aboard this suppository, will you? ". But he eventually did.
Some scenes involving police brutality were cut from the editing phase, including some sequences showing Jean Gabin slashing Le Coréen's character. And also the scene where Gabin fires a gangster lying on the floor. But this last scene remained in the film after director Lautner insisted in front the producers by bringing some young punks who told that the police really beat them up once on custody.