Continuity mistake: When Henry Pratt's lying dead after Helen killed him his head's turned to his left. When Miles is kneeling next to him his head's suddenly turned to his right. A shot later and his head's turned back to the left. Then, when Helen's on top of Miles, Pratt's head is turned back to his right.
Continuity mistake: When Matt's trying to call the police Hexina jumps on his back. He shoves her off onto the floor where she lands without hitting anything. Yet somehow she's got a broken nail which heals up after that closeup shot.
Continuity mistake: When Hexina chases Matt with the knife, she steps on the trigger of a camera, getting her picture taken. Simon sees this later and somehow it has Matt in the background despite him getting out of the way.
Continuity mistake: When Hexina falls to her death, she's falling face down. When a close up shot is shown, she's lying on her back.