Vortex (2) - S2-E1
Continuity mistake: When Martha Kent and Lana were talking about the meteor shower in the Talon Relief Center they sit down on the stairs. Lana puts both her hands on her knees. But in the next shot now her arms are outstretched in front of her, and now it's her elbows which are on her knees.
Revealing mistake: In the scene in which Jonathan shoots Lex, he is gently lowering and raising the barrel of the gun whilst shooting, even though there is a 'bullet-time' effect in progress. Maybe the sequence is shot in real-time, with the actors standing still and the 'bullet' added afterwards? Furthermore, would Lex really move that quickly in relation to the speed of the bullet?
Continuity mistake: As Clark walks up to Lex you can see the tip of Lex's cue stick is 3-4 inches away from the rail. Before Clark picks it up the stick is now right up against the rail.
Continuity mistake: When Clark lifts Lana back onto the bridge, from a shot from above, we see that Lana puts her left leg onto the bridge into a sitting position. They then cut to a different angle but now both her legs are still dangling and she eventually puts her right leg on the bridge first.
Continuity mistake: In the shot where Clark picks up Lex's cue stick, the balls on the table are spread out in an arch consisting of 4 balls. The shot switches to a low level shot looking at Lex and the balls at Lex's end, where the arch should be, are no longer forming an arch.
Continuity mistake: During the opening scene, behind Jesse you can see the vice principal walk up behind her and reach out as he's about to put his hand on her shoulder, yet the very next shot of Lana, in the background you can see he's just exiting a room.
Skinwalker - S2-E10
Continuity mistake: While he is being attacked by the wolf the foreman fires the flare gun with his arms spread, meaning that it would fly at an angle away from him. He then sees it arcing back from below toward him, impossible unless the flare changed direction and location in the air. (00:02:20)
Plot hole: Mayor Tate and Lex have a discussion about bribes and Tate says this is his 4th term (near the end of the episode, Lex is showing Mayor Tate an attack ad which is saying Tate has been the mayor for the past 12 years and Smallville can't afford another 4 years of Mayor Tate, so it's been 12 continuous years). In last season's episode "Crush", Pete gets a job as a summer intern on Mayor Spiegel's re-election campaign. So how is it possible for Tate to have been on his 4th term when in the previous year Spiegel was Mayor?
Vortex (2) - S2-E1
Plot hole: When Nixon and Jonathan are trapped in the crypt after the landslide, Nixon says he can't breathe, and Jonathan says this is because the landslide cut off the air supply. However, we can see beams of sunlight shining in. So, unless the ceiling of the crypt is made of airtight glass, that landslide didn't cut off the entire air supply.
Vortex (2) - S2-E1
Audio problem: When Lex talks to Clark, Clark clicks his flashlight on, and you hear the click signifying he has turned it on. But in the next shot, the flashlight is now off, without another click sound heard to signify that the flashlight was turned off.
Continuity mistake: There are several close up shots of the syringe that Dr. Hamilton is using to threaten Pete with and you can see that it is made of plastic. Clark uses his heat vision to overheat the syringe causing it to burst but the sound the syringe makes when it bursts is that of a glass syringe and not the plastic one he was actually using.
Vortex (2) - S2-E1
Continuity mistake: When Clark, Pete and Chloe were looking for Clark's father in the woods, Pete says: 'the twister must have dropped it here' and we see Chloe holding the map in her right hand. Cut to a different angle (as Clark runs towards the screen) and in the background we see Chloe holding the map with her left hand instead.
Continuity mistake: When Lucas is in the Luthor mansion talking to Lionel and Lex, he picks up and inspects the samurai sword, then returns it to the holder, hanging it on one peg by the strap. In the next immediate shot, it is resting between the pegs, as it was before he picked it up.
Continuity mistake: After Lex confronts Desiree about changing her name, Lex says 'we really need to discuss this' Desiree then kisses Lex and they both tilt their heads to their left. Cut to a different angle and they are both tilting her heads to the right.
Continuity mistake: After the credit card company calls the Kent's to confirm purchases made the night before, we see Jonathan holding a mug by the rim. They then notice the music coming from Clark's barn and go to investigate. Cut to a different and now Jonathan is holding the mug by its ear.
Continuity mistake: When Jonathan runs up to Lex, while he is unconscious, the first shot of Lex has his arm bent but not near his face. The shot switches to look down on Lex and now he is laying with his hand considerably closer than the previous shot.
Continuity mistake: Nell meets up with Lana to talk to her about moving to Metropolis. We see Lana going up to Nell while riding a horse. She then stops and is about to dismount when they cut to another angle but now Lana is dismounting yet again.
Continuity mistake: At Ryan's surprise welcome back party, Clark puts his right hand over Ryan's shoulder as he asks him "you knew about this didn't you?" Cut to a different angle as Ryan responds "I was tempted too" but now Clark's hand is no longer on Ryan's shoulder. Cut to Clark then back to Ryan and now Clark's hand is back on Ryan's shoulder.
Continuity mistake: The position of Clark's sleeve to the tourniquet change between shots. When Dr. Bryce first ties the tourniquet she does so at about an inch from the end of the sleeve. In the next shot, as Clark lies unconscious and nobody touches his sleeve, the tourniquet is tied around the sleeve and no longer on his skin. Just before Dr. Bryce sticks the needle in it's back to being an inch from his sleeve.
Skinwalker - S2-E10
Plot hole: Chloe says the coroner found teeth marks on the foreman's bones. During the attack, at the beginning of the episode, the foreman only got a couple of scratches on his face and the rest of his clothes were perfectly fine and hadn't, in any way, been torn up. It would have taken the wolf tearing through the clothes, through the skin and, finally, through the muscle to leave any teeth marks on the foreman's bones and that did not happen.
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