Continuity mistake: As Sean sucks electricity at the power station, his arms are bent in the first shot and fully extended in the next. (00:31:25)
Continuity mistake: As Victoria is being drowned in the bathtub, she appears very deep in underwater shots and only a few inches down in overhead shots. (00:26:00)
Continuity mistake: In the closeup when Zoe is introduced, the button just above her apron is buttoned. In the next shot of her walking through the cafe, it is unbuttoned. (00:07:35)
Revealing mistake: At the command center outside Martha is watching a monitor with the hostages on it and she asks "Where's Clark?". The next shot is one of Clark running down a hallway, inside the plant, using his super-speed. As he is running the red lights along the ceiling are revolving faster than they normally do and return to normal once Clark stops using super-speed.
Plot hole: Justin's power is telekinesis, which he uses to attack the doctor at the beginning of the episode. He shows that he is targeting the doctor's hands by blacking them out on the drawing, but he has absolutely no way to see what is happening in the elevator to know the exact moment when to drop it and cut them off. (00:03:30)
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: When Lana and Clark are sitting on top of the windmill, Clark's jacket changes from opened to closed to opened.
Audio problem: After he breaks the methane valve, Earl runs to the security camera and whispers, "You see what you made me do?" His whisper is heard at the proper volume by the Luthors watching the camera, but the speakerphone is on the desk ten feet behind Earl, making this impossible. Most surveillance cameras don't have microphones. (00:28:55)
Continuity mistake: As Pete demands Chloe's keys he raises the gun on her. As he does you can hear the sound of the hammer being pulled back on the revolver. In the shot of the gun, as Chloe gives him the keys, the hammer is not pulled back.
Continuity mistake: As Harry goes into the pond the second time the pylons are connected now with yellow crime scene tape when the camera is out over the water looking at Harry on the walkway. As the camera is in the water, watching Harry fall in, the pylons are gone, even though they should be in the shot, and are connected by a wire instead of crime scene tape.
Continuity mistake: For several shots during the early scene with the baby in the crib, the blanket changes back and forth from tucked up to the chin, up to the shoulders, and up to the stomach in different angles. (00:01:55)
Continuity mistake: When Chloe is kissing Justin the shot is behind him and her hands are not on his neck. The shot switches to behind Chloe and she does have her hands on his neck.
Continuity mistake: After Lex tells Martha that he'll do whatever he can to help Jonathan, she goes into Jonathan's hospital room. As she goes through the door, the blinds next to the door are closed. When the shot switches to show Clark standing at the other window, the blinds next to the door are open. Then, as Lex goes over to Clark, the blinds next to the door are closed again.
Continuity mistake: When Jonathan shoots Clark with the shotgun, in the slow motion shot of Clark as he first starts to take the hit there is nothing coming out of the gun or on his chest. When the shot moves to Clark's left he now has red hot shot fragments on his chest.
Continuity mistake: After the encounter in the meat locker, Lex and Clark talk outside Fordman's store. As Lex turns to leave there is a truck driving down the street in Clark's direction. When the camera switches to Clark, the truck, which should be in this shot going behind Clark, is nowhere to be seen.
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