In the opening scene when Rachel rushes to return home from the estate grounds, it is clearly late evening, with the blue of the sky still fading. Yet, as she returns to her room, Edward tells her it is about midnight.
There are two crows in the movie, one that is shown at the beginning, that is clearly seen as young and another in a scene where the situation becomes tense, is changed by some older, but both staying in the cage.
The road to the village shows fresh wear from tire treads, yet no vehicles are ever shown in the film.
When Rachel first leaves to go shopping, she has to reach through the bars of the gate to re-latch it, yet when she returns, she just pushes it open without unlatching it.
Closeups of Rachel's hands clearly shows she's had a recent manicure and that she also uses clear nail polish.
Neither would be likely for a financially struggling young woman in post-WW1 Ireland.
Nude shots of Rachel show that her armpits and legs are shaven which was not the custom during that era.