The PartyGoofs
Continuity
At the dinner party, Peter Sellers' red wine glass disappears and reappears.
The sax player is playing a tenor for the whole film until the end during the bubble scene when he mysteriously is playing a beaten up old C melody. Clearly he didn't want to get his horn ruined, but they should have used something else as it's a completely different instrument, different keywork and different color and different size.
Mrs Clutterbuck falls from a walkway into the swimming pool below and is pulled out soaking wet. She is carried up to her bedroom but her clothes are now dry.
Factual errors
There is no language called Hindustani rather its Hindi.
All cast lists, Closed Captioning, and C.S. Divot (Gavin MacLeod) introduce Michelle as Monet. However, when Michelle introduces herself to Hrundi, Claudine Longet says her name is "Michelle MANET." Is this a mistake or is it supposed to illustrate that Divot doesn't really care who she is, him being a casting couch predator?
When Peter Sellers wrecks the upstairs bathroom the sound of water flowing is clearly heard, but its level in the toilet cistern is at the top.
Revealing mistakes
After Bakshi (Peter Sellers) enters the house, soaked from the garden sprinklers, the make-up around Seller's eyes begins to run visibly.
When Bakshi lifts the lid on the toilet cistern, it is full of water. If it was continuously flushing, it should be empty.
There is no reason for the bidet to leak. Whilst the toilet breaks down after Bakshi has used it, he has not touched the bidet before it begins to gush water violently.
Miscellaneous
For the bit of the drunk waiter getting pushed on the dinner table by the opening kitchen door, Hrundi's full wine glass has been removed, probably to keep from staining the white table cloth. The water glasses are also arranged so they are not in the way of his first fall. After the head waiter chokes him, a red wine glass finally appears on the table for the drunk waiter to pick up and drink.
Audio/visual unsynchronised
In the scene mid-way through the film where the woman is playing guitar and singing, the sounds of the guitar strings are not in sync with her finger plucking. There are also sounds from other instruments like a flute playing along with the music yet she is performing solo with only the acoustic guitar.