Revealing mistakes: The "pills" that Roenick shows us more clearly near the end of movie are clearly Icebreakers mints. You can even see the little blue "flavor capsules" in them.
Revealing mistakes: In the closing scene there are no tire tracks in the fresh snow for the ambulance.
Continuity: The amount of snow falling outside the bus while it was on the road alternates between heavy when the camera points inward through the front windshield from outside and none when it points outward from inside.
Revealing mistakes: When the SUV flips over after having its tire shot out, a stuntman's elbow pad is visible in the window of the SUV while it is turning over.
Continuity: When Jake is washing his face in the mirror's reflection, his tattoos are still on his left (non-reflection) side, showing the camera was shooting through glass to simulate the reflection.
Revealing mistakes: When Beck is shooting out the window upstairs at a cop car, you can see the policeman running away, then suddenly, the policeman disappears.
Continuity: When the black cop is shot by the bus and goes down, he drops his gun in the snow. In the next few shots the gun is again in his hand, then back on the ground.
Continuity: At the end, when Fishburne walks away and the other cops are coming, it's dark. In the next shot, it's light.
Continuity: When Alex and Jake talk after Alex returns, you can see the amount of snow that's sticking to the window go up and down.
Continuity: Capra is still wearing the handcuffs when he and Iris drive off in the SUV, but after the crash, the cuffs are gone.
Factual errors: There are no holding cells in the basement of any of Detroit's precincts.
Revealing mistakes: In the forest scene, after shooting Duvall there was still a round chambered in Roenick's pistol but when Bishop took the pistol there was magazine in it.
Continuity: During the initial sequence of lasers and shots aimed inside the station, characters close the Venetian blinds. However, in subsequent shots, the blinds are open again.
Miscellaneous: After Roenick comes in from the fight he had with the guy in the bus, he has a bloody lip. After this point, it appears and reappears through out the movie, until it eventually is gone altogether.
Continuity: When Duvall is explaining his mathematical justification of why he believes the assault is warranted, he states that there are eight people inside the building, but at the time, he had no way of knowing how many people were inside the building, and this is verified later on when he asks Alex to tell him how many people are inside.
Revealing mistakes: When Roenick slides in to close the blinds after the lasers come through, he hits the radiator, which moves under his weight, suggesting it's not bolted down.
Revealing mistakes: Just after Roenick pulls the doc back from the front door after she tried to leave on her own: The lasers lines veers back and forth in much wider angles through the windows than would be coherent with the shooters being so far away that the story indicates. There's even some darting in a very steep angle upwards indicating that the shooters would be sitting few meters away from the building.