Revealing mistake: While there was a close up on Clark while he was asleep, you could see a small cut right above his eye, which is impossible if he can't be hurt.
Continuity mistake: As Clark jumps the fence, to stop Jonathan from falling, you can see Martha is standing in sunshine with the shadow of the barn well away from her. When Clark actually catches Jonathan suddenly Martha is standing in the shadow of the barn.
Continuity mistake: When Lewis says to Lex ".the bitch that set you up." he is holding the stick with the point in his wrist. In the very next shot he is gripping the stick by the side and not from the point.
Revealing mistake: When Lionel Luthor visits the Kent Farm and tells the Kents and Chloe that Lex is missing, Allison Mack is laughing when the group is shown from Lex's viewpoint in the barn.
Audio problem: In the beginning of the episode, Clark leaves for the Talon to meet with Pete. He is offered a ride by his mother, but says he'll run there instead. As he closes the door behind him, we hear the sound of him taking off in super-speed, but we can still see him through the glass in the door moving down the stairs in normal speed.
Continuity mistake: After Lionel and Professor Willowbrook finish talking Clark shows up to talk to the professor. As they talk, while the camera is behind Prof. Willowbrook, he has bright sunshine on his suit coat. When the camera is behind Clark the light on Prof. Willowbrook's right shoulder is gone.
Continuity mistake: As Lionel says "Good morning, Miss Sullivan." there is a camera change from Chloe's left to her right. When the camera is on the left, her left arm is down. When the camera jumps to her right her left arm is now in the middle of placing something high up on the layout board she is using.
Continuity mistake: The field trip is supposed to be on the 39th floor, as stated by Clark and the sign next to the elevator. The view outside the large windows as Lionel is talking shows that they are no more than 5 stories up.
Continuity mistake: As Alicia holds the kryptonite on Clark her hand turns between shots. While she says ".but you broke the rules first." there is a camera change. Before the change the frontal view of Alicia has her holding the kryptonite with the glowing part straight up. After the camera change she is now holding it so it points to her left.
Other mistake: Early in the episode, Clark uses his heat vision to blow up a police car. In the shot where we see the policewoman diving for cover, there is a front view of the car as it is exploding. The license plate on the front of the car IS a Metropolis plate, however, as the plate falls off, the white placard that auto companies and dealerships place in the license plate frames on new vehicles before they are registered and which are removed once plates are installed is visible. (00:07:10)
Continuity mistake: At the end of the episode, Perry and Clark arrive at the intersection to wait for the bus. They walk out into the intersecting road, and the bus arrives, positioned in the middle of the road, since they are standing in the right lane. Perry and Clark say their goodbyes, and a new shot of the bus from behind, shows the bus is in the right lane only as it starts up from the stop.
Continuity mistake: When Clark is faced with Nathan Dean at the Auto Wrecking lot, Nathan says "In a minute, neither one of you will care," (regarding Pete Ross' whereabouts). The next shot is of the blue car that Pete is trapped in with the windows blown out. Then the shot goes back to Clark and Nathan, and the cars fall onto Nathan. Clark is then listening for Pete and when we see a shot of the blue car being crushed, this time we see the windows being smashed.
Phoenix (2) - S3-E2
Plot hole: When Edge needs the vial of Clark's blood back, Edge holds Clark's parents hostage. Clark decides to use a sharp piece of kryptonite rock to cut his skin and give Edge a new sample. When Clark picks it up, and when he places the kryptonite rock on his skin, he shows no sign of the usual effects of the rock which include the green lines radiating up his arms.
Continuity mistake: At the beginning when Clark and Lana are on the small pier by the lake, it alternates from sunny to shady between shots during the scene.
Continuity mistake: As Lana says "I was thinking the same thing but we don't seem to be very good at it." there is a camera change as she says "but". Before the change she only has the red cup on the tray but after the change, even though she didn't pick it up, she has a red and a yellow cup on the tray. The other cup was on the table and jumps to the tray between shots.
Continuity mistake: When Chloe crashes through the bridge rails her windshield is dotted with raindrops. Just a few seconds later the blue truck hits her car from behind and now her windshield is dry.
Continuity mistake: After Dante says "...if you want to turn that tortoise into a hare just give me a call." he walks off and the shot follows him as he walks all the way over to a black car and starts to work on it. The shot returns to Clark and Pete and Dante is shown walking away again on the left side of the screen.
Continuity mistake: As Pete gets into his car the shadow from the car is extending out away from the passenger side of the car. As Pete starts to drive off, just a few seconds later, the shadow is now extending out past the back of his car.
Answer: The kryptonite only creates mutations when it reacts with the environment and an individual. Remember, the FDA and several environmental groups did check out Smallville after the meteor shower, but found no danger in the rocks. Obviously they're not always emitting mutating rays, or all the flora and fauna of the surrounding area would be horribly mutated.
Phoenix