Factual error: After dealing with the workers in the tunnel, Doomsday gets to the surface, kills all the Applecore workers and destroys their equipment and vehicles. Fires are everywhere from explosions and men scream as Doomsday crushes them. Once he finishes off the last guy, he walks a few steps away from the destruction and sees a deer just haplessly grazing on some grass nearby, only a few yards away from the Project Applecore. Only when the deer sees Doomsday does it decide to stop eating and take off running. Deer are afraid of loud noise. The explosions and men screaming only a few yards away would realistically have spooked that deer and just about any other wildlife in the area to run away. (00:11:15)
Factual error: Superman throws Doomsday through a small power grid in the middle of Metropolis and then Doomsday drags him back through it, nearly obliterating the plant completely. Yet with this power station destroyed, not a single building or street light in the surrounding area is affected by the sudden change of power flow. (00:22:20)
Factual error: After Superman plows through a building with Doomsday, Doomsday flies into a power plant. He goes over the top and snaps the power cables and hits a green box, causing a few of the red towers to fall. But when Doomsday grabs Superman and takes off running through the power plant, the damage there is suddenly way more extensive than what would have been for just snapping cables and causing the towers to fall. (00:22:20)
Factual error: Doomsday sees a little girl crying in the street and stops his assault on Superman to go attack the little girl. Superman quickly grabs Doomsday around the waist and jumps, rocketing them both up into space before Doomsday can crush her. The shockwave of this jump is seen as the tremendous force causes the street they were standing on to break apart and rubble fly. Yet the little girl is completely unaffected by the shockwave, it passes right through her and she is only feet away from the crater now left from Superman jumping up with Doomsday. (00:25:20)
Factual error: Throughout the scene where Toyman is holding a school bus full of children hostage, the sides of the bus are shown several times. In no shot does the bus ever have a bus number or a stop sign on the side. It is required by law in the US that school buses have the stop sign on them that extends out to stop traffic when children are exiting. And all school buses do have numbers if they are in use for identification purposes. (00:35:20 - 00:37:40)
Factual error: When Dark Superman begins X-Raying himself in the mirror at the salon, the reflection is not a mirror image, as his hair curl is still on the same side. (00:53:10)
Answer: In the comic book, Doomsday was put in a strait-jacket, strapped in metal bondage and placed in a cube like metal prison buried deep in the earth. It took him centuries just to break the bonds, then spent more centuries just punching his way out. With earthquakes, volcanoes and other natural disasters those events could shift Doomsday's prison to the surface.