Revealing mistake: When Superman launches the Eiffel elevator in space and he flies back to earth, a white rectangle surrounds him where his image was superimposed to achieve the flying effects. (The Ultimate Collector´s Edition Box Set).
Visible crew/equipment: Stage lights are reflected on the orange squeezer at the start of the movie.
Continuity mistake: During the fight in Metropolis, Zod throws a concrete wall which Superman explodes. When debris falls, a taxi stops but a grey car behind keeps moving. In the close-up the grey car is parked several meters behind the yellow one.
Revealing mistake: When Superman grabs the antenna above the pram, part of the antenna disappears because of the blue screen effects.
Continuity mistake: When the antenna falls, two men close to the pram by a yellow car hide next to a blue car. A shot later they're next to a yellow car, but a shot later they're running towards the blue car again.
Continuity mistake: When Superman rescues the kid in Niagara and holds him in his arms, in the wide shot the kid's waist rests in Superman's arm, but in the immediate close-up he is crouched and now the head rests on the arm.
Continuity mistake: When Ursa says to the Cosmonaut "What kind of creature are you?" her whole body is facing forward. He responds "Just a man" and in the next shot of her, her body has turned left. Then when she goes to grab his patch her body is facing forward again.
Revealing mistake: As Zod and crew blow people and objects down the street, it is obvious in some shots that they're all heading toward a painted studio wall.
Other mistake: The cab that slammed into Clark earlier in the film is seen coming around a corner during the confrontation. The amount of damage inflicted from running into the equivalent of a thick concrete pole should have rendered it inoperable, as the radiator was pushed back into the engine. Even if repaired, the front would have been repaired as well.
Revealing mistake: As Ursa slams the man's arm down, the section of the table their arms hit has been cut to make the stunt possible.
Continuity mistake: As Ursa goes to sit at the table in town, she starts to put her elbow on the table. After the cut, she starts to do it again.
Revealing mistake: As Non lifts the car to get the shotgun, the front of the undercarriage has a pile of dirt it, possibly to hide the lifting device.
Audio problem: As Superman's mom speaks in the recording, the reflection immediately to the hologram's right appears slightly out of sync with the main image. Also, there's one word the image says that the reflection's mouth doesn't mimic.
Continuity mistake: The kid fell backwards off the ledge and down toward the falls, but the distance shot he's face down rather than face up. It's also easy to see that it's a dummy because the hair color is different, as well as the body structure and limb movements are all wrong for a human.
Continuity mistake: As Zod bends down to pick up the Cosmonaut, the action is repeated in the reflection on the helmet.
Continuity mistake: After the Cosmonaut settles in front of Zod, there is nothing reflected in the visor if the helmet. A second later, after looking at Zod from the human's point of view, Zod and the moon buggy are reflected, even though the Cosmonaut didn't move the helmet.
Revealing mistake: The Cosmonaut Zod meets first pulls at his supply line. As he does, if you look closely the black wire used to make the hose move is visible.
Revealing mistake: As the astronaut that Ursa meets moves, the wires used to make him float are visible.
Other mistake: As Lois goes to climb under the lift, the one support she climbs over is bowed down a bit, whereas the others are straight, as if there were more than one take done.
Revealing mistake: In a close-up shot of the kid falling into the falls, one can notice the kid is just a dummy. Notice how his face is a lot paler than it was before. (00:39:35)
Answer: In the theatrical cut, nobody really knows why the green crystal restored his powers. However if you watch the Richard Donner cut, it is explained that the green crystal is a communication device that helps Superman talks to the residual essence/spirit/ghost of his father Jor-El. Before he died, Jor-El gave the crystal to his son. Jor-El anticipated that Kal-El might give up his powers, and he also anticipated that Zod might eventually escape the Phantom Zone, so Jor-El lets his son absorb the leftover energy of his spirit, thus restoring all his Kryptonian powers.
Matt Van Gogh