Other mistake: Early in the film, Jim Carrey is watching TV during a sports segment. He is watching Channel 7, the station he works for. This clip they showed was of actual WKBW sports director John Murphy. The clip they showed was taken directly from a real WKBW newscast, with the authentic news set, and graphics. However, when they show a clip of Ch. 7 News later, there are completely different graphics, and a completely different news set, both made for the movie.
Factual error: At the very end of the film Bruce is reporting on a drive for blood donors, and Grace leads him over to the booth to give blood himself - he is even wearing a tourniquet. However, he is supporting himself on a walking stick - he is not fully recovered from the injuries he received when he was run over, which happened when he was hit by a moving car - injuries which left him clinically dead. There is absolutely no way that a person who has suffered life threatening injuries and has undergone the (inevitably) intensive drug therapies and surgical procedures involved while under treatment in hospital in the fairly recent past would be allowed to give blood. There is no way that the Red Cross (or the US equivalent) would want to encourage people who have recently been hospitalised to try to give blood. Not only would that be the height of irresponsibility, they would be wasting precious resources and staff time turning away people who would not be allowed to give blood.
Continuity mistake: After the riot in the streets of Buffalo, Bruce meets up with God again in the Omni Presents building. They discuss how everything is going wrong. At the close-up shot of Bruce's face when he says, "What do I do now?" the frame is flipped. You can tell this because his hair is parted on the wrong side and his nose looks different. (01:15:20)Macalou