Factual error: When Doom reaches into the cab of the Dip vehicle and starts it, it doesn't jump. It is a modified military vehicle, and it's a standard. If you try to start a standard vehicle without pressing the clutch in to disengage the gears (the weasel driver left it in gear when he died), then the vehicle would lurch forward as the engine turned over.
Factual error: The red cars are seen traveling with poles raised on both ends. The wheel at the raised end of the pole, which collects power from the wire, must always be trailing the car. Basically, streetcars going forward have the rear pole raised and front pole lowered, and vice versa. They would not be traveling at normal operating speeds with the front pole raised, as that would damage the wiring system.
Continuity mistake: The number of wood slats on Baby Herman's playpen keeps changing at the start of the film. When his mom says goodbye there are eight slats at the front, and five at the side. When he escapes the playpen there are eight at the side, and when Roger realizes the playpen's empty, there are nine at the side and seven at the front. Additionally, the characteristics of the teddy bear changes, as well as the colors of the balls on the wood slats. (00:00:40)
Continuity mistake: In the scene where Valiant is in the bar and just learned that his friend has been laid-off he takes a drink but Dolores puts her hand over it. In the next shot she has a shot glass in her hand and a bottle, but when Valiant shows her the check, both the glass and the bottle are gone. (00:12:00)
Continuity mistake: When Eddie goes to meet Maroon with his accusations, Maroon is holding a distinctively brass colored gun. When Eddie attacks him, the gun is released by Maroon, and it instantly cuts to a shot of Eddie on top of him, an identical gun in hand. Then when they get up, Eddie tosses the gun aside. When Doom shoots Maroon through the window, Eddie dives for cover and once again the gun is amazingly in his hand. (01:06:20 - 01:07:15)