Continuity mistake: Shortly after their cell phone conversation, Lionel sees Lana and gets out of his car. In the next shots of Lionel, his car has moved position from behind him.
Continuity mistake: Clark has to save Lana from a bomb as she is unconscious next to it inside a warehouse. As the bomb explodes and Clark runs through the fire to rescue Lana in the overhead shot she is on her side. In the next she is on her back.
Continuity mistake: In the head on shot of the car that almost hits Mr. Altman you see the driver of that car react by turning his car to the left. In the very next shot, as Clark and Mr. Altman are just coming to a stop after Clark's high speed rescue, the driver is now turning his car to the right, as shown by which way his wheels are turned.
Continuity mistake: When Adam says "It's nice to be appreciated" Lex is looking at Adam. In the next shot, as Lex says "strange thing is." and now Lex is looking down at the file or piano.
Continuity mistake: Lex brings some comic books to Ryan at the hospital. He holds all of them with his left hand. He then shows 66 of the comic to Ryan and holds it with both hands. Cut to a different angle and now he is holding the comics with just his left hand once again.
Continuity mistake: After Lionel finds out about the wire that Lex has been wearing, he sits down and tells Lex to get out. As Lex leaves, in the wide shot, Lionel drops his hands down to his lap. In the zoomed in shot Lionel's hands are up to his face as he plays with the wire. There was no time for him to make that move between shots.
Continuity mistake: Lionel press conference about Lex's kidnapping only infuriates Rachel. She then picks up an axe and was about to swing at the tied up Lex when he manages to get his right leg free and kick Rachel backwards. As she falls backwards, we can see that she drops the axe off to her left side. Cut to a different angle but now the axe is over her head to her right side.
Continuity mistake: While in the line to claim their class rings, Pete holds a folded piece of paper (probably his receipt). As Clark says: "I earned that money.", Pete starts to unfold the paper. Cut to a different angle as Clark continues: "Besides, my dad said." but now Pete is looking at a completely unfolded piece of paper.
Continuity mistake: When Kyle goes to confront Rickman about coming to Smallville, Kyle is talking about how Rickman agreed not to do anything in Smallville and Kyle is pointing with his left hand. When the shot switches he is now pointing with his right.
Continuity mistake: As Clark is sitting in his barn's loft his mother enters while he watches a model of the solar system. In the shot when he turns it off the large red globe, which looks to be Jupiter, stops well to the right of the model's sun in this shot. When the shot returns to Clark, Jupiter is now partially in front of the sun. Clark had not moved his hand from the off switch so he didn't move the model by hand and the model would have taken longer to make another rotation to put in that position.
Continuity mistake: As Lana gets ready to throw the first ball there is a kid in a red, black and white shirt in the background and he is walking away from the scene. Just after she throws the ball the very same kid is calmly walking behind her again.
Continuity mistake: When Lana and Clark are sitting on top of the windmill, Clark's jacket changes from opened to closed to opened.
Continuity mistake: When Molly first starts flipping through the disks for Lex, she has a ring on her left ring finger. After Lex talks about just getting back Molly is shown still flipping through the disks only now the ring is gone.
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: Jason accesses Lex's computer and Lex catches him. After a discussion on an email Jason found Lex says "Burying ladies in the backyard isn't exactly a hobby of mine, Jason." Lex then just stands there staring at Jason. During their stare down the camera jumps back behind Lex and then back to behind Jason. During these camera changes the lighting on the left side of Lex's face changes. When the camera is behind Jason, Lex's left side is dark. When the cameras is behind Lex, Lex's left side is lit up.
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