Factual error: At the very end of the movie, Ichabod addresses to Young Masbath saying the final line "You'll son find your bearings young Masbath. The Bronx is up, the Battery is down and home is this way." However the Bronx was instituted only in 1898, a century later.
Continuity mistake: At the start of the movie where Ichabod is at the City of New York Municipal Watchhouse there is a medieval device to Ichabod's left, which is open and empty. In the following shot, there is a man standing inside with the doors closed around him.
Continuity mistake: When Ichabod is visiting the witch for information on the Horseman, we see them sit at the table where the witch chains herself to the wall and demonstrates how much reach she has and that she can't touch him. When she transforms, she knocks over the table and tackles Ichabod to the floor. Even if she was starting to pull the chains out of the wall like in the film, that still wouldn't have given her the extra foot and a half needed to tackle Ichabod to the ground. (00:45:00)