Detective Sergeant Tom Brant (portrayed in this movie by Jason Statham) is a character in a series of novels by Ken Bruen. This movie is an adaptation of one of them.
Brant is driving a Mercedes 560SEC Coupe. Near the end of the movie he is being followed by "Blitz" away from a funeral when his stock (period) 15-inch wheels suddenly become modern 19-inch shiny rims.
After being introduced to the "troops" at the station, when Nash arrives at his house and enters the kitchen, he is wearing an overcoat. As the camera changes shots, the overcoat is gone and he has a regular jacket on.
When Porter Nash is introduced to the force, the Superintendent lifts up a newspaper explaining that they are already under a media frenzy. The newspaper says that a second officer has already been shot dead before it actually happens in the film and the photo features a man, when the first officer to be shot was a woman.