Deliberate mistake: When Nico finds Hilda's body at the start of the movie, her left arm is shown next to her body, and her right arm is outstretched. When her death is shown later in the movie, both arms are outstretched when she lands on the floor. (00:05:50 - 01:30:55)
Deliberate mistake: The movie is set in "Harburg County", Pennsylvania, but there is no county in Pennsylvania called "Harburg." (00:13:38)