Continuity mistake: At the beginning, as the mother tucks the blanket up to the child's neck, she changes from both hands on the infant to one hand on the crib. (00:01:55)
Continuity mistake: When Sean is in the nurses office, having his temperature taken, the light on his left side is on. After the nurse wants to retake the temperature the light is now off.
Continuity mistake: When Kyle first confronts Rickman in his office and challenges him to a handshake, Rickman looks away. In the next shot on Kyle, Rickman is looking at him again. (00:13:20)
Revealing mistake: In "Rogue," just after Jonathan has been arrested, Clark walks into the house and punches a wooden beam. If you look closely, you can see the crack in it where it has already been broken. (00:26:35)
Continuity mistake: In the intro to the final scene, the top half of the loft doors are open with the bottom half being closed, yet at the end of the scene during the pullout, both the top half and the bottom half of the doors are open.
Continuity mistake: At the coffee shop when he intercepts Lex, Phelan suddenly acquires a cup of coffee from nowhere. (00:10:00)
Character mistake: Chloe hands Clark a newspaper with the list of jury members from Harry Volk's trial. As he reads the list he says "Rudolph Gage, Rita Garfield". After Clark realizes that his grandfather, Hiram Kent, is on the jury he hands the paper to Lana. A shot of the newspaper has the jury members listed as Randolph Gage, and Eve Garfield. Even young Harry calls her Eve when confronting Zoe at The Beanery.
Continuity mistake: When Jonathan is sitting down, before he tells Clark that he can't always be honest, in the shot from the other side of the table Jonathan is holding a book in his right hand as he is sitting down. When the shot switches to Clark's right, Jonathan is still starting to sit but now the book is in his left hand.
Visible crew/equipment: After Martha finds the money in the antique shop she tells the other woman she needs to be more careful, as they are walking in the room there is a boom mike shadow moving.
Continuity mistake: Right after Ryan makes breakfast for the Kents, he leans on a chair and sets the orange juice jug down twice. (00:05:35)
Factual error: When the bug kid crashes his car, he's driving a VW Beetle, which has the motor in the rear, therefore would not have shut off in a head on collision.
Continuity mistake: When Chloe and Clark are at the Torch after the pool incident with Shawn, Chloe is sitting down wrapped up in a green sweater and a blue jacket with part of her blouse showing. In the next shot, she is fully wrapped in the green sweater. Seconds later, her sweater is tucked into her jacket and her blouse is showing. (00:28:00)
Continuity mistake: When Ryan gets hit by Martha's car, his comic book goes flying out of his hand. When he falls to the ground, he's holding his comic book again.
Tempest (1) - S1-E21
Continuity mistake: The way the pillar is on top of Lionel changes in the scene. In the first shot, he's on his side and it lands on his hip. In the next shot he's now on his back and the pillar is going somewhat across his body. In the wide shot of him as the roof falls, the pillar is below his belt, almost perpendicular to his body. Then back to being on his stomach and part of his chest.
Other mistake: When Ryan gets hit by Martha's car, you can see he has both shoes on as he's going to the ground, and we never see a shoe flying through the air during the hit. Then James and Debra find the shoe in the middle of the street as they watch Martha drive off.
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