When Janet asks the policeman to tell their landlord that the rent money was stolen and the policeman responds to her the front door is wide open. They cut to a close up of Chrissy saying something to the policeman. Then they cut back to Jack and the policeman talking and now the door is closed.
When Mrs. Roper is trying to convince Mr. Roper to take the "kids upstairs" out to dinner, a boom mic enters the top of the frame.