Audio problem: When Phillip plays on the piano, the music doesn't match his finger movements.
Continuity mistake: When Rupert gives ice cream to Brandon, they are besides a wall between the living room and the entrance of the house but the shot later, they are on the other side of it.
Continuity mistake: When David is killed in the very first scene, the two men lay him neatly in the big chest, the rope does not hang out the side. But then one man bends over and discovers the rope halfway hanging out of the side of the chest. Plus it was knotted around David's neck anyway, so couldn't have been yanked out, it would have had to be untied.
Continuity mistake: The chest holding the dead man's body is almost waist high on all the characters in all of the scenes, except the last shot when Jimmy Stewart walks toward it. The chest is now about knee height on him, and he sits down beside it and comfortably rests his arm on the chest with the gun in his hand.
Continuity mistake: Jimmy Stewart has two ice cream sundaes in his hands, and both have a dark topping (likely chocolate) as he is talking to the character Brandon. The shot changes and the toppings change to one dark and one butterscotch (light topping).
Suggested correction: The ice cream toppings do not change. The chocolate has simply melted down the side of the ice cream, thereby appearing lighter.
Revealing mistake: In the opening scene when Brandon opens the curtains to let the light in, he is suddenly casting a shadow on to the couch, towards the window, as if the light is coming from behind where the camera is located. (00:04:15)
Other mistake: Brandon is wearing gloves but Phillip is not when they kill David. Afterwards, Brandon removes gloves from Phillip's hands.
