Up the Crick Without a Piddle - S7-E4
Visible crew/equipment: While Madam Fanny is rehearsing at the piano, behind her in the background, a woman comes down the stairs. It is not a waitress, and Rene and Edith are still in London.
More mistakes in 'Allo 'Allo!
Edith: Tonight I will sing as I have never sung before.
René: What, in tune?
Trivia: Carmen Silvera (Edith) was 18 years older than her on-screen husband Gorden Kaye (René).