Chief Belden's police hat comes off after Mannix punches him, but in the next shot, the chief is once again wearing the hat.
When the Highway Patrol officer is showing Mannix how the accident occurred, the figurine of the woman has a green shirt. A few seconds later the shirt is brown.
When Janet knocks Blake down the stairwell with the piece of furniture, he rolls down the stairs and lands unconscious on his right side. But when Mannix arrives to tie Blake up, he is on his back.
When Mannix and Janet are in the house, he looks around in an upstairs room then tells Janet to stay in it while he checks out the rest of the upstairs. But he didn't open a door in the back of the room to clear that area as he should before telling Janet to stay in the room.