When the man who wants Raven to steal the box is listening to her explain why she failed, he is wearing a red necktie that appears and disappears several times throughout the scene.
As Raven walks through the secret passage, she shines her torch on the walls and sees blood, but the blood disappears in the next shot.
The lock screen on Raven's phone shows the date in the British format as 10th October, rather than the American format as might be expected of an American girl's phone.