The film is set in the early 1800s, yet a statue of St. Therese of Lisieux (Therese Martin) is prominently displayed in the castle three times (at 17:26, 40:09, and 47:08). Therese Martin was not born until 1873. Furthermore, no statue of St. Therese was made or displayed until after she was canonized, in 1925.
When Col. Hassell arrives at the inn to meet Anton near the beginning, there is no glass on the carriage window when the carriage arrives at the inn. There is also no sign of broken glass when the carriage arrives at the castle, but a shot is fired through the carriage's glass window en route.