During the 'Architects Sketch' the window behind Graham Chapman is open slightly when he looks out at the 'idiots', but closed when he starts speaking to the 'clients' again.
During the Bishop sketch, The Bishop (Terry Jones) and his men run up the stairs to the assistance of a priest (Eric Idle) who is calling for help. One of the Bishop's men is used as a battering ram to break down the door. When his head bursts through the door, the entire set is slightly pushed over.