Other mistake: As Frank and Betty move the wardrobe a chair tips over by itself. Frank and Betty are nowhere near it - it is presumably attached to a wire which is pulled by one of the crew, but has no significance to the plot.
Some Mothers do 'Ave 'Em (1973)
1 other mistake in Going on Holiday
Starring: Michael Crawford, Jane Hylton, Michele Dotrice, Jessica Forte
Genres: Comedy
Jessica's First Christmas - S2-E7
Visible crew/equipment: When Frank is loading the lorry at the warehouse, he drives the forklift onto the lorry, then the lorry drives off while he and the forklift truck are still on the back. As the lorry pulls away you can see the camera crew on the other side of the road filming the next shot.
Frank: I didn't know what a girl was until I was twelve years old.
Betty: You must of done.
Frank: How could I. I'd never seen one.
Trivia: Michael Crawford was the producers' third choice for the role of Frank Spencer. The part had been previously turned down by both Norman Wisdom and Ronnie Barker.