Plot hole: During Clark's rescuing Lana from the fire in the basement, Clark wakes Lana just before he is grabbed by the coach. Clark then tosses the coach all the way across the room and into a wall. Lana makes no mention of how Clark could toss a full grown man across a room like that even though it happens right in front of her face.
Continuity mistake: In the head on shot of the car that almost hits Mr. Altman you see the driver of that car react by turning his car to the left. In the very next shot, as Clark and Mr. Altman are just coming to a stop after Clark's high speed rescue, the driver is now turning his car to the right, as shown by which way his wheels are turned.
Continuity mistake: When Adam says "It's nice to be appreciated" Lex is looking at Adam. In the next shot, as Lex says "strange thing is." and now Lex is looking down at the file or piano.
Plot hole: Outside the school, as Clark is talking to Jordan, there is a lot of people in the surrounding area. Clark looks up and sees the coach standing in the street and the car slams on its brakes to avoid hitting him, this causes the tires to screech thus drawing attention to the incident. Clark realizes that the coach is about to be hit by the car and uses his super speed to save him. Yet nobody seems to wonder how he suddenly appeared next to the coach just in the nick of time.
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