At about 1 hour 28 min, Richie Maguire and DI Robert Lewis are conversing next to a police "panda car". In the shots where the camera is facing Richie Maguire, the antenna is in the vertical position; when the camera is facing DI Robert Lewis, it's laid horizontally on the roof. This is also a factual error because that type of antenna is for window glass mounting only. It cannot operate through a metal car roof, as it is seen.
In one of the last scenes Lewis handcuffs himself to the baddie using rigid handcuffs. These must never be used for this purpose, only for handcuffing a persons wrist to his own wrist. The baddie is shot and they both fall backwards. If you look at Lewis's face you can see he has hurt himself for real. The last scene shows him with his arm in a sling for a genuine injury.
Richie claims that "vermin" such as pigeons can be shot on a Sunday. This not true - no wild birds can be shot on Sunday or Christmas Day, for any reason.
Near the end, one of the band members shoots the murderer with a double barrel shotgun. When the camera next shows the man who had been shot with the shotgun lying on the ground, there was no sign of injury. If he had been blasted with a double barrel shotgun from the distance that he was shot, his whole front should be damaged. Also, as Lewis was standing next to him, he would have caught a few pellets as well.
When Laura shows Lewis the garrote wire found in a wheelie bin, she says Frisch's skin is found on it along with some leather. Frisch is not the professor who died, she is the faculty member who is waiting with Kitten and who assesses Samantha Wheeler's screen after professor Wheeler is murdered.