Insurgence - S2-E12
Continuity mistake: When Lex speaks with the Lieutenant, watch Clark and Jonathan in the background. They are seen standing by a News Now van and looking up at the Daily Planet. When the camera cuts to them, they are shown walking past the News Now van again.
Continuity mistake: When Russell shows Crissy the lighting on the stage, we see him put a blue filament on the light with both his hands. He then drops his right hand as they cut to another angle but now he is lowering his right hand again.
Continuity mistake: After Pete confronts Clark about the missing space ship in his tool shed, Pete gets into his car and we see Clark put his right hand on the door of Pete's car. Cut to a different angle as Pete drives away but now Clark's hand is no longer on the door.
Continuity mistake: Pete arrives when Lana was interviewing Clark for a video that she would send to Whitney. Lana then asks Pete: 'want to give it a shot?' We then see Lana holding the view finder of the camera with her left thumb and index finger while the rest of her fingers in outstretched. Cut to a different angle (as we see Pete) but now the rest of her fingers are no longer outstretched.
Insurgence - S2-E12
Continuity mistake: When Lana is meeting with the Small's over coffee at the Talon and Mr. Small gets more coffee for himself and is wife, he picks up his cup and his wife's. Then when he comes back he puts down the coffee for himself and Lana.
Continuity mistake: When Clark gives his "I understand you, dad" speech at the table, he puts his left hand on his mom's right shoulder. She then holds Clark's hand with her right hand. Clark then walks across the table and as they cut to a wider angle Martha Kent's right hand is suddenly on the table.
Continuity mistake: At the bar, the agent looking for Jessie calls the barkeeper. He then proceeds to fold a piece of paper and puts down the pen which he was holding onto the bar. Cut to a different angle (as he takes out a photo of Jessie from his coat) but now the paper is unfolded and he is holding the pen in his hand again.
Continuity mistake: After Clark sees Whitney and realizes that he may be Tina Greer the next scene is at the school newspaper The Torch. The first shot of the computer, as the camera pans past it, has a story about Whitney's return up front with the story about Tina Greer's "suicide" behind it. Even though nobody touches the computer in the time between shots the next shot of the screen has just the story on Tina Greer and Whitney's story is completely gone.
Skinwalker - S2-E10
Continuity mistake: When the wolf jumps out the window of the Luthor mansion there is no blood on the glass shards that are left in the window. As Clark goes to the window, there is, all of a sudden, a lot of blood present on the glass.
Continuity mistake: In the kitchen, Martha collapses and Clark catches her just in time. Jonathan then rushes to his wife and puts his right hand on her cheek and his left hand on Clark's shoulder. Cut to a close up of Martha as Jonathan calls her name but now he has both his hands on Martha's face.
Continuity mistake: As Clark walks into his grandfather's motel room, his hands are behind his back. He turns to face his grandfather and both hands are now in front of him holding the photo album. The next shot shows him in the foreground raising his left arm from his side to hold the album. (00:31:30)
Continuity mistake: When Ian is dragging Lana towards the dam, his double can be seen in the background dragging Chloe. The double is on Chloe's right side pushing her. Cut to a close up as Chloe says "Ian you need help" but now the double is behind Chloe and is pulling her.
Continuity mistake: As Jonathan and Martha drive away in the truck, we see Rachel for the very first time and she has both her hands in her coat pockets. Cut to a close up but now her hands are outside the coat pockets.
Skinwalker - S2-E10
Continuity mistake: Joseph, Kyla and Clark are at the Talon, in the scene after Joseph is bailed out of jail. Martha comes in and walks over to the three of them. The next shot has her stopped next to Clark, with no forward movement to indicate she is still walking to him. In the shot after that she is still walking up to Clark.
Continuity mistake: The woman uses her right hand to get a swab for DNA testing from Clark. At first, we only see her right hand near Clark's face. Cut to a different angle as she says "There, now that didn't hurt a bit did it?" but now her left hand is close to Clark's face.
Continuity mistake: When Clark arrives late for school in Lex's car, he is stopped by principal Reynolds who tells him that he should have been there four minutes ago and points at his watch with his right hand. Cut to a different angle but now he is pointing at Clark with his right hand.
Continuity mistake: While Clark is talking to the agent that he has pinned to the wall, with the billiard table, the balls near the gun change their positions between shots.
Continuity mistake: When the agent goes to the Luthor mansion and confronts Clark about Jessie's whereabouts, Clark uses his speed to push the billiard table into the agent and jams him against a wall. As he does, the billiard balls obviously move due to the force Clark put on the table. Cut to the agent and later on Clark and we still see the billiard balls on the table yet they are no longer moving. It was too quickly for an object in motion such as a billiard ball to come to a complete stop given the force Clark exerted on the table.
Continuity mistake: When Martha is in the kitchen and starts having a coughing fit from the toxin, she drops the pitcher of lemonade. The pitcher lands on its side and breaks, but in the next shot, the broken base is positioned upright, sitting level on the floor, the jagged broken edges waiting to impale Martha.
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