When Daphne and Velma are nursing the tire marks, which Freddy ended up with after being ran over by Red Herring's Bike, Daphne is dressed as a nurse and Velma is dressed as a doctor. Then after Velma says "Aha", Daphne and Velma are wearing their regular clothes again.
When Daphne rules out Red Herring as the Culprit, Her tights disappear momentarily, making her appear bare-legged.