Continuity mistake: When Ursa sits down to arm-wrestle, a man with a red jacket who was sitting several feet to the left, suddenly appears on the back close to the guy with a Coors T-shirt.
Continuity mistake: The watch on the left hand of the cop holding the binoculars while watching the Eiffel Tower, appears and disappears between shots.
Continuity mistake: When Ursa descends through the White House window, she is facing the back of the cop holding a gun. In the next shot she lands facing somewhere else, the cop now being by her side.
Continuity mistake: When Ursa grabs the snake, in the close-up her badge appears skewed. In the rest of the shots the badge appears straight.
Continuity mistake: The coat hanger in Perry's office disappears between shots.
Continuity mistake: Non smashes Perry's glass but a second later the glass is back in place.
Continuity mistake: After Non smashes Superman against a metal structure which gets totally crumpled, Superman stands up and the structure is undamaged.
Continuity mistake: In the Fortress of Solitude, when Non is (green screened) flying towards Superman, Ursa and Lois disappear.
Continuity mistake: When Superman lands by the truck there are no people behind him. In the next shot there are a lot of people running around behind him.
Continuity mistake: In the first scene, when the guard gets caught off-guard by Non his right arm is on the side, in the close up it is bent to defend against Non. A frame later it's down.
Continuity mistake: After crushing Zod's hand, Superman sends him flying away. Luthor's head turns around twice.
Continuity mistake: When the ring falls on the villains, Non is looking down and a split second later he is looking up.
Continuity mistake: When Non is about to break Perry's desk in half, Jimmy and Lois are standing very close to each other. A split second later they're farther apart.
Continuity mistake: When Lois prepares orange juice, Clark lowers his left arm and sneaks it behind his back. A second later the arm is up.
Continuity mistake: Zod makes a short jump from the white car to the Marlboro truck, but in the next shot we see the two cars are several feet further apart.
Continuity mistake: In East Houston, the army jeep is passing by a brown car, then Ursa talks and we hear the jeep engine coming close, but when the image focuses back on the jeep it is several feet behind the brown car, instead of being in front of it.
Continuity mistake: In East Houston, while the helicopter fires at the 3 villains, a soldier runs behind Ursa and she is left totally alone. In the next shot he is behind her, running away again.
Continuity mistake: When Clark crosses the street before being hit by a cab there's barely no people behind, in the next shot there's a lot more.
Continuity mistake: When Clark comes out of the river one shot shows the back of his jacket with one half up and another down. When the angle changes the entire jacket is up.
Continuity mistake: When Ursa throws the sewer lid to Superman, first she is standing in the middle of the street but in the next shot she is close to the curb, by a yellow cab.
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