John Cleese has stated that Basil's line about the table tennis table not being "in absolutely mint condition, but it could certainly be used in an emergency", is his favorite line from any episode of Fawlty Towers.
At the end of the episode, there are clearly three hotel inspectors. However, only two of them (John and Brian) are named in the closing credits. The first inspector says "Twenty-six bedrooms, twelve with private bathrooms." The second inspector says "Yes, well, why don't you have dinner here, and Chris and I can try the Claremont." The 1st inspector replies "OK. The owner's one Basil Fawlty." The third inspector, Chris, is not credited as he does not speak at all.
The scene in which the wine is 'corked' involved improvisation on the actors' parts. John Cleese and James Cossins were unaware of which way the wine would go, if at all. Loosely scripted dialogue was therefore at hand.
The only evidence of Basil ever smoking is when Sybil takes back all the matches (she is "just lighting up") and gives him back just one, in the opening scene.
Bill Morton, whose friend overheard the hotel inspectors in a bar, was named after Bill Morton, the vision mixer for the series; he is the only member of the crew mentioned in the series.