Claire's hair changes between shots after her musical outburst
Mrs. Swanson attempts to remove the watch from her dead husband's perfectly flexible corpse in the casket. Embalmed bodies resemble wax statues, thus this flexibility would not be possible.
When Ruth and David are having lunch and Ruth mentions the buyout offer from Gilardi, David says "He [Nate] spent his entire life doing what *he* wants". The camera then cuts to an over-the-shoulder shot of Ruth from David's perspective, and his jaw is obviously moving as if he's speaking but there's no sound of him speaking.
Michael C. Halls marker is clearly visible when he goes to greet Mrs. Swanson at the door.