Continuity mistake: In the scene where Sid James is trying to teach Barbara Windsor to count by using her two best assets, watch his coat. From the front Sid wears a white shirt, brown waistcoat and matching top-coat. From the back however, Sid has lost his top coat and is in his waistcoat and shirt sleeves. As the scene cuts between the two shots, Sid's coat disappears and reappears.
Continuity mistake: When Jack Douglas is climbing the wooden ladder in the bell tower, his right leg gets caught in the bell rope set as a trap by the Reverend. However, when he is shown swinging, it is his left leg that is in the rope.
Continuity mistake: When Kenneth Williams & Jack Douglas are at the 'The Old Cock Inn', the candle on their table gets bigger and smaller throughout the scene. At one point it has nearly burnt completely down, yet when Jack Douglas comes out of the toilet for the second time, it has grown back to at least six inches.
Continuity mistake: When the Rev Flasher is talking to the innkeeper at the pub, Maggie is smoking a pipe, but in the next shot, she is now drinking from a lidded tankard.
Continuity mistake: When the organist plays "O God Our Help" for the first time at the church service towards the end of the film, the Rev Flasher takes Tom from the organ and head off towards the vestry. At this point, Flasher enters the vestry first with Tom behind him, but when we cut to the inside of the vestry in the next shot, Tom is now entering first followed by Flasher.
Continuity mistake: When the Rev Flasher announces during the collection the congregation will sing Hymn 202 for a third time, we see Sergeant Jock Strapp, Captain Desmond Fancey and Sir Roger Daley at the back of the church. After a quick cut to Flasher, two men approach Fancey and Daley for their collection, but Strapp is nowhere to be seen.
Continuity mistake: When Jack Douglas is swinging after getting his foot caught in the bell rope in the tower, he initially has nothing on his head but a few seconds later he is wearing his hat.