Continuity mistake: Chloe is sneaking around inside the warehouse that Lex is using to hide the space ship. After she is found by a security guard she turns back around to look in where the ship is. When she does a shot from her POV shows the fan blades spinning faster then they were in the shot before and after when we are looking at Chloe through the fan.
Continuity mistake: At the Daily Planet, after the opening credits, Clark tells Chloe that he found his mom unconscious in a field. He did not find her in a field, he found her in the driveway in front of the house. Later, at the hospital, Clark tells his father that he found her in the driveway.
Other mistake: Lois' car has the plate number "AJH 927." This is the same plate number that Senator Jennings had on his car in a previous episode, "Exposed."
Factual error: In the 5th season episode "Lexmas," Chloe says she needs Clark to deliver the Daily Planet's Toys For Tots contribution because of a Teamsters' Strike. However, the Toys For Tots program is run by the United States Marine Corps Reserve, and collection and distribution is handled by Marines and Reserves. The Teamsters have nothing to do with it.
Continuity mistake: As Chloe is trying to get Clark to help her deliver presents Clark says "Chloe, you didn't have to go there." Right before he says this the two of them start rounding the corner to go down the next hallway. As he is saying the line they are back in the first hallway and start rounding the corner again.
Plot hole: Clark is delivering presents for Chloe. In the overhead shots looking down on Metropolis he super speeds from building to building and he only spends like one second in each building before going to the next one. This doesn't match what is shown while we see him leave presents by the various trees inside the apartments. In those interior shots he spends 5-10 seconds in each room. The overhead shots are not sped up. Not only do these times not match up but he would also be slowed down to open the doors or he would constantly be breaking them down.
Plot hole: At the start of the episode Samantha is shown putting the sniper rifle together during the start of the speech. The second time we see this scene, after getting the backstory during the rest of the show, the scene plays out that Samantha is backstage kidnapping Lois at the start of the speech. This would mean that Samantha would have to be in two places at once and she doesn't have any powers at all.
Continuity mistake: At the beginning of the episode an announcer calls Jonathan's name and he appears almost immediately. Later on we see what happens backstage and when we hear the announcer call Jonathan's name. The second time through he has time to say a few last words with Lois, go to the edge of the curtain and take a breath before he steps out on stage. The timing of the two scenes don't match.
Continuity mistake: When the officer tries to disable the bomb, the read out displays 19 seconds. After he drops it, the display shows 29 seconds.
Continuity mistake: Lex's aide is shot in the back as he makes a run for the door. When he goes down he slides head first almost all the way to the door. A few moments later, just as Flynn shoots out the security camera, in the security monitor image Lex's aide is now in a different position.
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.
Other mistake: When he takes Lana to the Fortress of Solitude, Clark squeezes a rock and when he opens his hand we see a perfectly cut diamond. Problem here is that in the real world, diamonds don't come out of the earth already cut and shaped. (00:04:20)
Continuity mistake: Clark and Martha show up at the barn. The interior rear view mirror is missing when looking out from inside the car, but it is there when looking in the car from outside.
Character mistake: While Clark and Chloe are at Daily Planet, Clark asks her what is wrong with her mother. Chloe responds that her mother left when she was twelve years old. In the episode Lineage, Chloe and Clark are looking for Rachael Dunleavy and Chloe says her mother left when she was five.
Plot hole: Clark uses his X-Ray vision to see the remains of the girl in the wall, which seems to establish the wall is not made with lead. However, he only reacts to the Kryptonite bracelet inside until he is aware it is there, despite the fact he should have been able to feel its effects long before that.
Continuity mistake: Victor is up in Clark's barn loft using his laptop to read an article about his 'death'. In some scenes the laptop is turned toward Victor, while in one scene, as he says he expected to see angels when he woke up, the laptop is now turned at an angle so that the camera can be seen on the screen.
Continuity mistake: When Victor is going into Lois' apartment with Clark and Lana, he is holding his jacket over his wound to soak up all the "blood". Later, when he goes to see his girlfriend, he is wearing his jacket, but his jacket has only a small stain now.
Continuity mistake: While Chloe and Lex struggle for control of the gun Simone puts both arms down to her side. The shot switches to a slow motion shot of Simone getting shot and instantly Simone has her hand on the jewel again.
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