(at around 40 mins)When the evil force is ripping the pages out of James Johnston's bible, it can be seen that each of the pages are in fact all the same.
(at around 1h 12 mins) When the bed sheet is being pulled up over Betsy, right when the lightning flashes, a string or wire is clearly visible.
(at around 40 mins) In a night scene where the light from the candles and fireplace are systematically blown out, James Johnston immediately picks up his Bible and begins reading in the dark.
This movie is set in 1817-1820. Richard and Betsy were married "shortly after" Betsy's father died. The walls are adorned with their wedding photos, but photography was not introduced until 1839. Even then the pictures would have been small hand held daguerreotypes, not big framed enlargements.
In one scene the sky is shown with clouds, and an obvious jet stream or contrail streak to the left.
Some of the female characters have hairstyles that are obviously modern-layering and fringes. Betsy is also seen wearing her hair loose at a party, which she would not do as a girl old enough to attend parties and think of getting married. Putting up one's hair for the first time was a mark of adulthood, signifying that the girl was old enough to be courted.
(at around 38 mins) Right after John Bell gets knocked out by the door slamming shut, the "spirit" re-opens the door. A hand can be seen quickly pulling away from the knob on the other side.
Usually, boys and girls sat on opposite sides of the schoolroom, not intermingled.