When the female counselor hops on the motor-cross bike with Roger, her helmet is not fastened, and then the she takes off by accidentally hitting the throttle. Then when the bike finally stops, we see her helmet is fastened.
Towards the beginning, there is a scene when a counselor is explaining the rules to the males (after they were checking out some of the females of the camp). When the counselor is walking slowly, he accidentally hits Jaleel White (Steve Urkel), then the angle switches and you see the counselor in a different position that contradicts him hitting the White with his arm/shoulder.