During the car chase scene, Burt's red police car loses the front windshield, then later in the chase scene the car is seen again with the windshield intact.
Burt drives an unmarked Dodge Diplomat for the majority of the film yet when it gets shot at it becomes a Plymouth Gran Fury (note the grill).
During the car chase, one of the headlights on the bad guys car falls off; between shots, that headlight reappears/disappears.
During one scene where partners Burt and Ernie are chasing a suspect, Burt is in the passenger's seat with his seat belt on. Ernie then opens the door to pull him out, and suddenly, his seat belt is no longer on, and he is pulled easily out of the car.
Urine samples (especially for drug screening) are never left unattended. The nurse immediately puts it through a small door to the lab which is then taken by a lab technician on the other side.
There is no such illness called autotoxia hemotosa or Wexler's Curtain.
During the car chase underneath the elevated roadway, even the other cars not involved in the chase are running the stop signs.
The shadow of the camera crew can be visible on the ground towards the end of the car chase. (open matte 4:3 "Fullscreen" version only)
When Burt is hanging from the window washing rig, saying "I'm not gonna die", you can see the head and face of a crewman just over his right shoulder. (open matte 4:3 "Fullscreen" version only)
The movie takes place in Seattle, but there are freeway signs that mention Vancouver. The movie was filmed in Vancouver, Canada.
During the first locker room scene. (open matte 4:3 "Fullscreen" version only)