The director (a big RAFC supporter) insisted that actor Gene Bervoets (a Beerschot supporter) whistle the anthem of RAFC in a scene where he's in the car (Beerschot and RAFC are both football clubs in Antwerpen, with 100 years of enmity dividing their fans). Gene Bervoets, however, agreed to do as requested immediately. Since his character is a complete bastard, he thought it quite logical that he would be an RAFC-fan.
In the first scene in the café, Bieke en Vincke are watching an episode of "Buiten de Zone" (season 2, episode 2: "Kitsch en Kunst"), a highly popular youth series in the 1990s. The actor who plays Bieke's father in the movie, Dirk Roofthooft, appeared several times in this series.
Bieke's father who gets shot resisting arrest at the beginning of the film, is clearly shot on his left side of the chest. But in the shot right before he lays still, we see the gunshot wound on the other side, then it flips back again when he's down.
The laser mounted to Ledda's Beretta is not in a consistent position. Laser mounts of this era are difficult to install and it appears there are two prop guns. One has the laser mounted properly, the other has it pointed down at a 5° angle (which would make it useless for aiming). In closeups, the two are switched between in single scenes, so this is clearly a mistake, and does not indicate the character dropped the gun and misaligned the laser at some point, for example.