When Jenny makes her escape from the warehouse she takes a Beretta pistol from the Hessian. After she picks the lock she holds a Glock which later changes back to a Beretta.
Benjamin Franklin says to Ichabod "the answer lies under the alarm clock." The alarm clock was not invented until 1787 and Ichabod was said to have fell on the battlefield in 1781. Thus, Franklin would have no knowledge as to what an alarm clock was.
All junctions with US Route 9 through Sleepy Hollow, New York are in densely populated residential and commercial areas.
Ichabod Crane is chastised by Benjamin Franklin for not learning his alphabet. Crane stated that Franklin "forced me to study it endlessly". Crane however has an eidetic memory, and would not have to study it 'endlessly'.