
Continuity mistake: When Jodie hits the deer her vehicle spins out. As it is spinning the headlights are not projecting any kind of visible beam. After the car stops, and she is facing the deer she hit, the headlight is now projecting a very bright beam to illuminate the deer on the road.
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