Continuity mistake: The blood on Lana's face is different then how it was in the previous episode. While at the crater in Commencement she has two distinct lines of blood on her face. One on her left cheek is thick and the one on the right cheek goes down past her lips. While at the crater in this episode the left line is then while the right line is shorter. These two scenes should be identical since Arrival picks up right after Commencement.
Continuity mistake: When Clark's parent show up at the house Clark hurries up and acts busy. He grabs 4 boards and moves them from one part of the kitchen to the other and leans them up against the wall. When Clark turns around to face his parents there are only 2 boards leaning on the wall.
Continuity mistake: When Gabriel shows up to help Chloe the shadow of his bike shows it to be about noon. According to the show it should only be between 6:30 to 7:30am.
Continuity mistake: When Lois and Arthur are sitting at the end of the dock, (before Arthur begins to hear the piercing ringing sound) the position of the bikini lace hanging down Lois' back keeps changing between shots.
Continuity mistake: The water level in the glass that Lex taunts Aquaman with changes levels throughout the scene.
Continuity mistake: When Clark first enters the club, the stripper on stage is taking her top off, then in the next shots of her, she still has her top on.
Continuity mistake: When Clark's truck stops rolling over the hood is stuck open. As Clark pops up from the front seat the hood is down for the camera to get a shot of Clark.
Continuity mistake: Clark is poisoned by a silver kryptonite splinter. When Clark is stabbed, the splinter is in his left index finger. Then, in the scene with Fine after class, (less than twenty minutes later,) Clark is seen rubbing his right index finger.
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.
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.
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.
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.
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.
Continuity mistake: When Lana goes to see Lance, who's packing up the serum, you see 5 syringes strapped in, 1 with serum in it. When Lance hits Lex and his case falls open, you can see the 5 syringes still strapped in, but now none have any serum in them. When Lance goes to pick up the case, only one syringe is strapped in, and it's in the wrong spot, next to some blood, and one syringe out of the strap lying in the open case.
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