When Colin throws a temper tantrum after being exposed to an open window, the camera returns to focus on Colin for reaction shots several times during the argument. In some shots, he's dry and his face is pale; in others, he's flushed and sweaty.
In the final scene, while Mary, Dickon and Colin are playing Blind Man's Bluff and Colin discovers his father in the garden with them, the blind fold (which Colin has pulled up on his head like a headband) changes disappears when the camera is looking over Colin's shoulder.
Mary hears crying at night, gets out of bed, puts her dressing gown on, and wanders along the corridors towards the sound. At one point the dressing gown is fastened at the waist; the rest of the time it's open.
The scene after the credits shows a key being turned in a lock and a door being pushed open as if it's in the garden. This opens to the left while that into the garden opens to the right.
When Mary first meets Colin, as she enters his room, she is holding a oil lamp. The oil lamp, however, has a light bulb, not a wick and flame.