Continuity mistake: Doomsday throws Superman at a building and he slams near a window, people looking out. It cuts to a close up as Superman falls to his knees and the people in the window suddenly change around. (00:19:05)
Continuity mistake: As Lois is starting up the helicopter with Jimmy, you can see the seats behind them and how they are designed, lots of lines and not plain, with the seat belts coming out about mid way down. But then as the helicopter is zooming by the camera, you can see now the seats are now plain looking, and the belts come out much higher up. (00:19:20)
Continuity mistake: After Lois and Jimmy get in a helicopter, the scene changes back to Doomsday and Superman fighting on a street. As Superman is attacking Doomsday, there is a yellow car in the street behind the creature. Superman then gets a few good hits off, and sends Doomsday flying backwards through the air. Suddenly the yellow car has turned into a large 18 wheeler truck. (00:19:40)
Continuity mistake: When Lois spots Doomsday and Superman from the helicopter, Jimmy is beside her holding his mouth trying to not throw up. His camera is around his neck and you can see the button to snap pictures is on the right side of the camera at the top. But them moments later when it cuts back to them, Jimmy is holding his camera to snap pictures and suddenly the button has vanished off the right side, and his finger is on the left side as if he is pushing the button there. (00:19:50)
Continuity mistake: From the air, Lois spots Superman and Doomsday fighting below, and points. It then cuts to Superman and Doomsday battling by some rubble. Cuts to a close up and then back again as Doomsday smashes Superman into the ground, and now the pile of rubble behind them has changed. (00:19:55)
Continuity mistake: Doomsday throws Superman at a wall and pile of rubble. There is a red car stuck in this rubble. Doomsday then begins pounding on Superman's head and smashing him further into the wall. But in the shot where Superman falls out of the wall, the red car has vanished. (00:20:10)
Continuity mistake: Jimmy zooms his camera in on Doomsday as the creature spots him and begins climbing rubble to jump at their helicopter. As Doomsday is climbing up, it cuts to a shot from behind him and suddenly the rock and the way he is standing on it changes. (00:20:30)
Continuity mistake: After seeing Jimmy and Lois in their helicopter, Doomsday leaps through the air and grabs it. The window of the chopper cracks and the frame where he grabs it bends with his grip and his weight. But then as Superman grabs Doomsday, a shot from the outside of the chopper shows the window and frame fully intact, no damage. (00:20:40)
Continuity mistake: When Superman goes to set down the chopper that Jimmy and Lois are in after Doomsday trashes it, the air intake vent on the top of it is smaller than seen before. Then when he sets the chopper down and lets Jimmy and Lois out, the design of the intake vent changes completely. (00:20:45 - 00:21:20)
Continuity mistake: Jimmy kicks the side of the helicopter where Doomsday is holding on and Doomsday falls, but then grabs the chopper by the landing bars. His left hand is forward of the metal piece that holds the landing bar to the frame of the helicopter as he uses his right hand to grab into the side of the helicopter. But then after Superman pries Doomsday's right hand away and goes to cut through the connecting metal with his laser vision, Doomsday's left hand is suddenly holding on behind the connecting metal. (00:21:00)
Continuity mistake: When Superman pulls Doomsday off the chopper, there's a metal panel stuck to Doomsday's fingers and you see it still there as Superman throws him away. Then the angle changes just before Doomsday smashes through the roof of a building but suddenly the panel has vanished from his fingers. (00:21:10)
Continuity mistake: When Superman sets down the chopper, there is a building behind them with some people standing around. It cuts to a very brief shot of inside the chopper as Lois removes her seat belt and then cuts back to outside the chopper, and suddenly the people standing around have moved. Also the air intake on top of the chopper changes shape and goes from a lighter blue to darker blue. The damage to the windshield becomes more extensive between shots, the glass part on the bottom of the front of the chopper goes from being two parts to one solid part, and the broken landing leg changes from a light blue to being white like the body of the chopper. (00:21:25)
Continuity mistake: After Superman rescues the helicopter Lois and Jimmy are flying and sets it down, Lois reaches up and undoes the top half of her seat belt, and Jimmy is just sitting there in shock not touching his. It cuts to a different angle and Superman walks up. Lois suddenly has her full seat belt off, and Jimmy is helped out of the chopper by Superman, without ever taking his seat belt off. There was not a time laps between shots. (00:21:25)
Continuity mistake: After Superman has set down the chopper, Jimmy and Lois step out and Jimmy places his hand on the chopper blade and begins to barf. But then the camera cuts to an angle behind Jimmy as he barfs and suddenly he is much closer to the tip of the blade. (00:21:30)
Continuity mistake: Once Lois and Jimmy are out of the chopper, Doomsday bursts up from the rubble of the building and begins charging at Superman, who then charges back at Doomsday. As they collide, you can see down a side street at the buildings, several cars in the road, and some rubble. Doomsday and Superman bounce off each other and slide back in their respective shots, and then go at it again in a fist fight. The side shot then shows the same street, only now some of the buildings on the left side are noticeably different, the cars have vanished from the street, the smaller pieces of rubble in the road have changed around, and the street lines in the road have vanished. (00:21:55)
Continuity mistake: After getting hit by Doomsday's elbow, Superman hits the ground and slides across the road on his face, mostly his chin with his arms flailing around behind him. It cuts to a different angle and instantly Superman has pushed up off the ground with his hands and is rolling over. (00:22:00)
Continuity mistake: After Superman saves Lois and Jimmy in the chopper, he and Doomsday get into a fist fight for a moment, Superman getting a few good hits off, followed up by Doomsday spinning and slamming Superman in the face with his elbow. The shot cuts to a different angle as Superman staggers away and falls, and suddenly the number of spikes on Doomsday's shoulder goes from 4 to 1. (00:22:00)
Continuity mistake: Having saved the chopper, Superman and Doomsday go at it again in the street. As they are punching, you can see buildings on the left side of the street, and in the distance there is a small blue building with yellow windows and a taller building beside it to the left with a large sign on top. It then cuts to a close up of Superman getting a good punch to Doomsday's face followed by Doomsday smashing his elbow into Superman's face, and suddenly another building appears between the small blue building and the other one, and the large sign has vanished off the building that was beside it on the left. (00:22:00)
Continuity mistake: After Superman recovers from getting elbowed in the face, he knees Doomsday in the chin and then flips over him and throws him hard at a building. But if you watch closely, the building it shows him being thrown at is different than when it cuts to the next shot to the building he hits and goes through. In fact it the building he hits looks more like the building off to the left of the one that he was thrown at. (00:22:05)
Continuity mistake: When Superman throws Doomsday through a building, Lex Luthor is shown watching from his office from an over the shoulder view from his perspective. It then cuts to an angle from further behind him and suddenly an antenna appears on the building, and the design of the windows change. (00:22:10)
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.