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: When Ross is bitten by Gus, his hand lies vertically on Gus' head. A shot later it lies horizontally. (01:41:29)
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: Gus serves Brad an extra shot of vodka. He takes a sip and says "yeah, perfect." In the following shot the club in his fist is protruding less than in the previous shot. (00:44:06)
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.
Continuity mistake: At the snowy terrace, Gus tells Ross that Superman "is bad." Ross has his index finger pointing at his temple, but a shot later it's lowered. (00:54:53)
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.
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.
Revealing mistake: After getting blasted by the big missile, as Superman goes to leave the rock face, the surface flexes, showing it's fake.
Revealing mistake: As Superman takes off from the junkyard, the background can be seen through him.
Continuity mistake: When Superman takes Clark's glasses, he folds one arm of the glasses in. A moment later, that arm is extended, and he folds both arms and crushes them.
Revealing mistake: After throwing Clark into the compacter, Evil Superman flies to the control booth. As he walks through the door, the background can be seen through him.
Answer: The only reason that Gus was working with Ross, Vera and Lorelei was because he stole money from the company he worked at. To avoid going to prison, Gus was forced to do anything that they wanted. After realizing that his computer was designed to do anything it was ordered to, including killing Superman, Gus removed a small screw which shut down the power momentarily but, after the computer brought itself back online, Gus attempted to destroy it with an axe to save Superman. Superman saw this and realised he was wrong about Gus and after the computer was destroyed decided to help Gus find a job.
That makes sense, thank you! Been bugging me for years.
Jen Hen
You're welcome.