When the quarterback throws a pass, in the background, police officers run onto the field for no apparent reason. When Jimmy mounts the horse moments later, we again see the officers run onto the field.
When Jimmy Dix shows the senator's bodyguards the "bom" picture through the window of the BMW, they shoot at him completely shattering the window. In a subsequent shot, when Jimmy is yanking on the seat belt, you can see the window undamaged.
The senator's bodyguards shoot a single shot through the passenger window of the BMW, yet when it pulls into the parking space at the stadium and Jimmy gets out, you can see four bullet holes in the window.
When the thugs prepare to throw Jimmy Dix over the side of the bridge, they drag him to the rail facing forward. In the next shot, he's turned around the other way and falls back-first onto the car hood.
When Milo's car hits the roof of the house, it clearly hits flat, and full-on. Yet, in the next shot of the car, the car is spinning through the air, and in the final shot, the car lands upside down in the pool. The car should land right-side-up in the pool.
Joe takes his revolver and a Desert Eagle from the hit man in the alley, yet when he runs around the corner into the gun battle he's shooting the revolver and a Beretta 92. A moment later, he has the Desert Eagle again. Guns change type (and hands) throughout the scene.
When Dave is thrown off from the overpass, he falls onto the car on the road below and his red hat quickly flies off his head to the left of the screen. In the next shot, his red hat gently falls off the hood of the car.
When Mike's, the other PI sleeping with Joe's wife, car blows up it is an 87-90 Model year Mustang GT convertible. When the car settles on the ground, it is revealed to be an 84-86 model year based on the front headlight and bumper design.
During the shootout outside of the strip club, it is raining hard throughout and until the end of the scene. When Jimmy kneels down next to Corey's body, however, the rain stops and restarts again to finish the scene.
From the dialogue we know that the opening football game is being played at the Brown's home stadium in Cleveland, but by their uniforms, the police who run onto the pitch are clearly the same LAPD officers who feature in the later LA based game.
When the camera cranes down behind Joe as he's making jokes with the Furry Tom puppet, a crew member, standing next to a ladder and other equipment is visible in the background to the right. This has been corrected in the Blu-ray release.
Reference is made by both Marcone and Senator Baynard to the "Senate Commission to Investigate Gambling in Professional Sports". Senate and House of Representatives panels are referred to as "committees"; "commissions" are special panels appointed by the President of the United States.
The goof items below may give away important plot points.
Near the end of the movie, when Milo is setting up to shoot Senator Baynard, we are given two alternating out-of-sequence shots of the senator. First, he is standing back several feet from the window with some people and a drink in hand. In the second, he is standing next to a chest-high window with both hands on the top edge of the glass. When we see the senator again, he is in the same standing-back shot and then again at the window.