Other mistake: Fleeing the Headless Horseman, Ichabod Crane and his horse tumble down a cliff and land in a lake. They are completely submerged but when they come out of the lake they are both completely dry.
Other mistake: Just as Ichabod Crane places his coat across a small stream of muddy water so Katrina can cross, Brom Bones rides his horse through the water, creating a large splash. Ichabod winds up covered with mud and sitting in the water. Brom scoops up Katrina and rides off with her. There is not a speck of mud or water on her, on Brom or on the horse.