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.
Revealing mistake: In the ice cave, Superman throws a plastic S at Non. The wires moving it are visible.
Visible crew/equipment: When Non crashes Perry against the ceiling, a crew member's hand is seen holding Perry.
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.
Revealing mistake: During the big fight in Metropolis, the close-up of the pram shows its empty or with blatant bundled pieces of fabric to simulate some sort of baby.
Continuity mistake: When Superman falls on the Marlboro truck, the part reading "Ma" gets more crumpled after Superman leaves the truck compared to when he landed on it.
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.
Visible crew/equipment: Wires holding Superman are visible when he is about to stop the elevator.
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.
Revealing mistake: When the Empire State antenna falls down the wires holding it are visible.
Audio problem: Most of the times when the French terrorists talk, their lips are not in synch or their mouths don't move.
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.
Continuity mistake: When the News Beat reporter arrives, the shadow on the satellite dish changes significantly in a couple of seconds.
Revealing mistake: Near the end when Zod and his crew are blowing everybody away, there is a shot of two cars going into a department store and one flying right to left. There are also two "people" running away in this shot. They're dummies. One of the cars hits the person and he wobbles. Incredibly obvious. These aren't mannequins from the store either; they're on a track and follow a path from right to left.
Revealing mistake: When Zod picks up the guy in East Houston, you can see right through the guy. He's transparent.
Revealing mistake: When Superman is saying, "No, don't do it! The people!" you can see Christopher Reeve is trying his hardest not to laugh.
Continuity mistake: Lex sits in the President's chair and lights up a cigar. A shot later, it has swapped hands.
Answer: Superman was be able to kiss Lois in such a way that the heightened emotion wiped out her memory of his identity. To answer your second question, even though Lois promised not to tell anyone, Superman decided he does not want even her to know his secret identity.
Matty Blast