Jessica's First Christmas - S2-E7
Other mistake: When Frank open his front door to Mr. Jackson the walls around wobble.
Other mistake: The walls of Frank's house wobble whenever he opens the front door.
Some Mothers do 'Ave 'Em (1973)
2 other mistakes in season 2
Starring: Michael Crawford, Jane Hylton, Michele Dotrice, Jessica Forte
Genres: Comedy
Moving House - S3-E1
Revealing mistake: At the beginning when Frank is directing the vans, we see that one gets its windscreen broken by a ladder from another van. However, the glass breaks just before the ladder touches it.
Betty: Don't get so depressed Frank, you've only been out of work two days. Mr Rogers hasn't worked for six months.
Frank: Mr Rogers is 86 years old!
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.