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.
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