Communication Problems (a.k.a. Theft) - S2-E1
Visible crew/equipment: In the scene where Polly tells Manuel to go and fetch toilet paper for Mrs Richards, the boom microphone shows up at the top left for a few seconds.
Visible crew/equipment: Basil runs out of the kitchen and stops Doctor Abbott and starts talking to him. The shadow of a boom mic appears on the wall to the right of the screen twice as he talks to him. (00:15:25)
Visible crew/equipment: When Basil's trying to persuade Sybil about the woman in the guest's room, the shadow of a boom mic appears on the top wall.
Visible crew/equipment: After Mr. Johnson refers to the Torquay guide as the 'world's shortest book' and leaves the hotel, you see a boom mic coming in at the top of the screen for about 3 seconds.
Visible crew/equipment: When the Hamiltons arrive, Mrs Hamilton says 'May I introduce my husband.' The boom mic is seen at the top of the screen.
Visible crew/equipment: When the Hamilton's are talking to Sybil, Basil enters and Mrs Hamilton says 'Harry finds it too gloomy'. At the top of the screen the boom mic is visible.
Visible crew/equipment: When Basil says to Mr. Hamilton "I'm sorry if it wasn't wide enough for you, a lot of the English cars have steering wheels" the boom mic can be seen in the top left corner.
The Kipper and the Corpse (a.k.a. Death) - S2-E4
Visible crew/equipment: In the kitchen scene with Basil, Sybil and chef, Basil says, "Would you believe it, I give him his breakfast, I take it all the way upstairs." At this point, the shadow of a boom microphone on the wall to the right is visible.
The Kipper and the Corpse (a.k.a. Death) - S2-E4
Visible crew/equipment: When Mr. White asks if Basil can clean their room later the boom mike shadow is visible on the door behind Mr. White.
The Kipper and the Corpse (a.k.a. Death) - S2-E4
Visible crew/equipment: When they discover that Ms. Tibbs has fainted in the office the boom mike shadow is visible on the wall to the right.
The Kipper and the Corpse (a.k.a. Death) - S2-E4
Visible crew/equipment: When Polly is on the phone with the undertaker and she says "I'm afraid somebody's died tonight", the boom mike is visible to the right of the screen.
The Kipper and the Corpse (a.k.a. Death) - S2-E4
Visible crew/equipment: When Basil, Manuel and Sybil enter the office and find Miss Tibbs fainted next to the corpse, the boom mic appears on the righthand side of the screen next to the fan on the wall. And when the camera switches back to the full shot of all the characters, the boom mic appears again.
The Kipper and the Corpse (a.k.a. Death) - S2-E4
Visible crew/equipment: When Dr. Price asks who found the dead guest the boom mike is visible above him.
Visible crew/equipment: When they are in to see Sybil, as they switch on the light, the boom mike is visible on top of the screen.
Visible crew/equipment: When Virginia shows the cakes she's brought with her the boom mike is visible above them.
Answer: A possible explanation can be found here: http://tviv.org/Fawlty_Towers/Waldorf_Salad Quote: "This is, of course, sarcasm, as southern California in general and Los Angeles in particular is famous for its palm trees".
Mortug