Out-takes from the closing credits of the Peter Sellers' "Being There"

I knew about the source-novel (haven’t read it), and I knew about author’s troubles with The Painted Bird.

What I didn’t know until today is there is a similar problem with Being There, which has been charged with plagiarising another Polish novel:

I’d have to read both to form a strong opinion. From the synopsis, the genesis seems clear – but Kosiński’s take seems to have a much different point. His central character is not trying to keep up appearances, he doesn’t even understand others are taking him for something else.