Continuity mistake: When the roller-skate girl grabs the trolley. In the close ups she is bending to the front, in the wide ones standing straight.
Revealing mistake: At the chemical plant, just before Superman takes off to save the people trapped on the roof, the wires are visible.
Continuity mistake: When Superman first pulls the stack down to use as a slide for the workers, the bottom where it came out of the roof was a dark color. When the people go to slide down, it's all silver colored.
Continuity mistake: After Gus unscrews the computer, the lights go off and Superman's corner becomes dark. From the opposite angle it's perfectly lit.
Continuity mistake: When Gus disconnects the computer Superman lies flat on the floor. A shot later his right shoulder is raised, and his body rests on his left side.
Revealing mistake: During the wedding and tornado in Colombia, huge rocks fall on the people's heads and shoulders, but they stand-up harmless or react calmly, revealing they were hit by fake prop rocks.
Audio problem: When the tornado in Colombia starts, two women sitting outside the church start crying "Mira pa'rriba" among other lines, but her mouths are not moving.
Continuity mistake: The shot outside of the bus where Jimmy and Clark are shows a woman and a man sitting on the front seats. In the shot inside the bus they disappear.
Continuity mistake: When Gus breaks the lattice in pieces and skis away, in the immediate wide angle all the falling wood and debris has disappeared.
Revealing mistake: When Gus flies off with his skis, note that the wooden lattice is already broken before his crash to allow for the stunt.
Plot hole: Gus could not know that Superman was in Smallville in order to give him the fake Kryptonite.
Continuity mistake: After Clark kills the bad Superman, he has dishevelled hair but after he flies it's now perfectly combed again.
Other mistake: When Superman uses his heat vision against the mirror, the beam should be reflected just like in Superman 2 with Zod.
Character mistake: When Gus is programming his new salary raise he mistypes Overide instead of Override.
Revealing mistake: During the Pisa tower scenes, the sky is always the same, plus the balloons in the stall have the exact same position, revealing not only that the shot is a chroma, but that both scenes were shot the same day.
Continuity mistake: When Superman struggles to stop being dragged by the computer, there is debris all over the floor. When the computer explodes the debris disappears.
Factual error: At the start we see a blind man and his guide dog, who runs off after a smaller dog. Guide dogs are specifically trained not to do this before being given to their owner.
Revealing mistake: As Superman takes off from the coal mine, there are two dark lines over him. That was an attempt to mask out the wires.
Other mistake: As Lorelei is held on the wall, there appears to be a chrome ball attached to the belt she has on to give a reference point, and animation was added to complete the scene.
Answer: There were rumors that Hackman was angry with the Salkind Brothers (the producers) for firing director Richard Donner, though Hackman later disputed saying that. His explanation, though he may have been downplaying the real reason, was that he had a number of other movie projects at the time, and he also did not wish to continually play the same villain in an ongoing movie series.
raywest ★