Continuity mistake: Chloe makes an $80 bet with Mxyzptlk at the beginning of the episode. When he pays her in the Torch office, he peels off seven 20-dollar bills for a total of $140 instead of the $160 it should be. (00:09:00)
Continuity mistake: Just before the final play of the game starts there is a shot of the scoreboard. The scoreboard reads 4th and 10 (yards) with 10 seconds to go. The announcer then says it is 4th and 1 with 10 seconds to go.
Continuity mistake: When the offensive line is first shown, as they sit on the bench, the shot is of them from behind. In that shot the team jersey numbers are in this order 89, 46, 8, 66, 1. Then the camera view changes to be in front of the players only now going from the players left to their right is 99, 46, 8, 66, 89.
Continuity mistake: When Clark is in the barn throwing footballs through the tire. He starts out with four footballs on the rack, but after he throws two, there's only one ball left.
Continuity mistake: Lois hands two boxes of decorations to Clark for Chloe's party but in the next shot he is holding just one box. The other box reappears when they turn to go into the barn.
Continuity mistake: When Lex comes into Lana's place to confess that he was the reason Jason got fired, we firstly see Lana putting some things into a cardboard box. Then during the following shots, the items visible at the top of the box keep on changing between shots.
Continuity mistake: While Clark is chained up, Chloe uses her fingernails to dig into Clark's chest. You can see that since Clark has had his powers taken away her fingernails draw blood. In the shot of Clark screaming in pain you should see where the blood came from the scratches but there is no blood visible.
Continuity mistake: After Clark gives Chloe the piece of paper with the list of cars that checked into the hotel, Chloe holds the paper in front of a folded up newspaper. Between shots, the newspaper turns the direction it faces. Then in the next shot, Chloe is only holding the piece of paper, and the newspaper that she was holding behind it has now disappeared.
Continuity mistake: After Clark saves Lex from the ring of fire we see the area that was burned by the fire. The candle that Shannon used to light the alcohol is no longer on the floor. Since the candle was in the fire it should be partially melted and there would be some evidence of it.
Continuity mistake: As Clark says "Eve Andrews was wearing two earrings when she died," during the line there is a camera change. Before the change Lionel has both arms on the table, but after the change he has one arm up examining the earring.
Continuity mistake: When Clark and Alicia are talking by the ice rink, the way Alicia holds her red cup of hot chocolate keeps changing between cuts.
Continuity mistake: After Clark heats up Alicia's cup of hot chocolate with his heat vision, the steam coming from the cup is thick and rapid in the first shot, but in the next shot hardly any steam is coming from the hot drink.
Continuity mistake: Alicia's hair keeps changing as Clark holds her in his arms. In some shots the hair on her right side is messy. When the shot switches to a close up, her hair becomes neatly combed and tucked behind her ear. All of this occurs after Clark burns the rope she was hanging by.
Continuity mistake: As Clark and Geoff are driving, the first shot of the SUV as it comes around the corner shows the ground is wet and the wipers are going. During their conversation the windows are constantly being rained on. Geoff points to the stadium and they arrive a few minutes later and as they drive into the garage you can see the street is dry.
Continuity mistake: After Lois and Clark find out that Cooper dies, and after Lois leaves, while Clark and Geoff talk about how Lois is trouble Geoff hair keeps going from neat to slightly messed up. When the camera is behind Clark, Geoff's hair is all shaggy on the left side of his face. When the camera is behind Geoff, his hair is fixed so that the loose strands are tucked behind his left ear. These changes repeat throughout the scene.
Continuity mistake: After Lois hits the dog, she exits her car and runs to the dog. As she passes the back of the car, her tail lights are off. When she reaches the dog, her tail lights are on.
Continuity mistake: Clark goes to see Lex about the dog. Lex, who was about to start a game of pool, breaks a fresh rack. Lex then goes to make his second shot from near the side pocket and as he does you can see there are two striped balls near the rail close to Lex's cue stick. Just after he takes his shot those balls are gone even though those balls had not been hit.
Continuity mistake: After Krypto comes around the fence we hear one of the two guys say "You got all the bags out of the truck, right?". The camera then pans over to the van and you can see, under the rear of the van, two gas containers. There is a metal one on the left and a plastic one on the right. Krypto starts to run for the truck and we see the containers again only now the metal one is on the right and the plastic one is on the left.
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