While at the house in the Lake District, the reaction to Sarah being pushed to the ground by Charles is genuine. Meryl Streep actually hits her head on the floor and when Jeremy Irons acknowledges, she nods, giggles, and reorients herself in position next to him.
Early in the film when Charles takes a horse-drawn carriage to visit Ernestine, the horse changes between shots (confirmed by the number of "stocking" feet it has).
Early in the film, as Charles is going on to the jetty to warn Sarah, his cape changes in how it is buttoned from shot to shot.
When Charles visits the garden and his bride-to-be is firing arrows, she loads a new arrow as she sees him. Then there is a cut to a closer shot, and she is loading the new arrow again.
Charles approaches the shore on a steam powered launch from the north. The next shot is also a shot in motion, suggesting from Charles' viewpoint, of Broad Leys, a white house high up on the shore where Sarah is working. Except the view of Broad Leys is as though from the south.