When Basil and Sybil are talking to the public health inspector in the kitchen (on his second visit), Basil breaks two bottles of wine. When he removes the second bottle, there are two bottles remaining on the rack, but when the camera cuts away and then back when he breaks it, there is only one bottle left on the rack.
The cat's slice of veal, which Terry cleans up to cook for the hotel inspector, can still be seen on the preparation table after having been served to the inspector.
A Local Authority Environmental Health Officer [Health Inspector] would, as a matter of standard policy, NEVER take a meal in a restaurant which he/she has just carried out an inspection of, due to the risk of the establishment concerned subsequently claiming that the Local Authority had given an unofficial "Approval" by doing so. Such an action may also, as in this case, compromise any potential prosecution for breach of Food Hygiene Regulations, on the grounds that the establishment could claim in court that EHO demonstrated confidence that food served there was safe, despite criticism.
The back door from the kitchen, leading to a backyard with various crates and the shed where Basil the rat is kept, is placed in such a way that the backyard would have been at the front of the hotel.
A sign saying "Wooburn Grange Country Club" (the real name of the filming location) is shown above the front driveway to Fawlty Towers.
From where Mr. Carnegie is sitting he should have an unobstructed view of the rat scurrying under the table on the other side of the room.
When Manuel knocks the veal onto the floor, Polly walks backwards towards where the poisoned veal is on the floor, and slips on the veal by mistake. She then retrieves the veal from the fridge, where it is subsequently knocked onto the floor, and mixed in with the piece she slipped on.