Factual error: While in the convenience store, watch the arcade screen the punks are playing, they are getting very excited about the game, however anyone who has played StreetFighter 2 will notice that they are merely looking at the demo version and even the words "insert coins" are displayed on the screen. Still, if it makes them happy...
Revealing mistake: When Curt asks the Riverman zombie to open the gate for them, Riverman's right arm has been blown off by a scientist, leaving him with only the robotic arm components. However, if you look you can see his real arm visible under the robotic one. This occurs in several shots during this scene.