Plot hole: When Olive gets in the motorcycle sidecar to go to hospital to have her baby, her weight lifts the bikes rear wheel off the ground. Stan rides on the rear of the bike seat to keep the wheel on the ground. However, Stan never intended to get on the bike until this problem occurred but he was holding a motorcycle helmet from the start of this scene.
On the Buses (1971)
1 plot hole
Directed by: Harry Booth
Starring: Doris Hare, Reg Varney, Anna Karen, Michael Robbins
Genres: Comedy
Continuity mistake: In the last scene, when Stan boards his bus inside the depot, the registration number is "WNO476" but, as soon as he drives out the front entrance, it changes to "VNO857".