Revealing mistake: After coming out of the Marlboro truck, Superman grabs Zod by his feet. When he sends him flying away, Zod's been replaced by an obvious doll.
Continuity mistake: When Zod is trying to heat up the truck's gas tank, while Superman tries to cool it the number of cars around changes dramatically, with no order whatsoever.
Continuity mistake: During the big street fight, Ursa grabs a flag pole. It is either in the shadows or lit, depending on the angle.
Continuity mistake: During the street fight, after the sewer lid scene, Zod lands on a car with his legs next to each other. A frame later they're spread apart.
Continuity mistake: When Non grabs Superman from behind, Supermans hands are down to his sides. When Ursa comes to hit Superman with the flagpole, Superman's hands are now up by his chest and under Nons grip.
Continuity mistake: When Clark walks down to the river to help Lois get out of the water, he falls on the water and she is swimming 4 meters away. When the angle cuts she is half a meter away.
Continuity mistake: The log that Clark cuts to save Lois from drowning changes style between shots.
Continuity mistake: Non enters Perry's office and kicks a plant which makes the coat hanger next to it wiggle, but not fall. When the angle changes, about a frame later, it is on the floor, several feet away from the first position.
Continuity mistake: Superman is putting the antenna back on the Empire State. first its base is brightly lightened, despite the antenna being on top. When he is about to anchor it, a split second afterwards, the base is totally dark.
Continuity mistake: After Superman holds the antenna falling on the woman's pram, in a matter of 3 seconds the parked cars she was standing in between (a yellow cab and a black car) come much closer together.
Continuity mistake: Lois is in the diner and the waiter serves her a Coke and leaves. Angle changes, the bad guy sits next to her and the waiter appears serving the Coke again. In the next shot, the angle changes again and he disappears.
Continuity mistake: In the diner, whilst Clark is asking the bad guy to step outside, the waiter is leaning over the baddie's right shoulder. When the angle changes he is leaning on the left shoulder.
Audio problem: When the villains are trapped in the Phantom Zone glass Zod cries out something against Jor-El, but his mouth isn't in sync with what he says.
Continuity mistake: Atop the Eiffel tower the climate keeps changing from sunny to cloudy within seconds depending on the angle.
Continuity mistake: Zod throws the Sheriff's rifle away and it lands next to the wheel. When the angle changes it has moved behind the wheel.
Continuity mistake: When Lois is making an orange juice the position of the oranges differs between wide and close shots.
Continuity mistake: After Superman crushes Zod's hand, his hair gets wet and the fringe appears combed as a toupee.
Continuity mistake: During the scene where villains arrive to the Daily Planet, Jimmy Olsen's haircut changes from long to very short.
Continuity mistake: When Clark comes back to the diner to take revenge, a dish next to the bad guy suddenly appears.
Continuity mistake: When Super arrives at the Daily Planet to defy the 3 villains, the outside shot shows three piles of books lined along the window. From the inside, all of the books are piled to the right. Also, the number of trophies on the bookshelf on the right, and the type and number of books changes between shots.
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