Revealing mistake: In the flood scene, you can see six inch boards on all the doorways keeping the water from spilling into adjacent rooms. (00:28:23)
Revealing mistake: In the scene where the kid sneaks into the butler's private quarters and sits in his chair, the butler sneaks up behind him and scares the kid. When he is sneaking up behind him, the camera shot is supposed to be the butler's point of view, but you can easily tell it isn't really. Watch closely as the camera goes right over the coffee table without making any noise, or without moving the camera.
Answer: Molly is wearing all gray suits and gray shoes.