Due to the rules used to determine wet runway takeoff distance (Accelerate-go to a screen height of 15 feet on wet runway vice a 35 foot screen height for a dry runway) and use of thrust reverse credit for calculating the wet runway accelerate-stop distance, it is possible for the calculated wet runway takeoff distance to be less than the calculated takeoff distance for a dry runway. This is clearly an artifact of the rules used to calculate the wet runway takeoff performance, not actual aircraft performance. Therefore the rules require that the wet takeoff distance >= dry takeoff distance.
References:
FAA Wet Takeoff Performance Video (see discussion starting about 5:00)
https://www.youtube.com/watch?v=vEc_M9PqUJc&feature=emb_logo
Boeing Document D6-1420, Jet Transport Performance Methods