Revealing mistake: The woman becomes possessed while the police are attempting to arrest her. She turns her head around and cracks her shoulders so she can walk at them backwards. They did not change her hand positions, so her right hand is where her left should be and vice versa. (00:11:00)
Revelations - S1-E10
Revealing mistake: When Kieran looks at his phone in the car, the image of Emma calling him is upside down. The image was added after the filming was done.
Sicut Cervus - S2-E6
Revealing mistake: When Strand is sitting on the bed with Thomas, Thomas takes his last breath. Seconds later, you can see Thomas swallow.