There was also the case of a mayoral aid who was forced to resign for using a word that starts with the same four letters as the N word, but meant stingy or mean and had been around since the 1300s. Due to forum rules I can not say what this word is, because it sounds like the N word
Widening this up, there is also the issue of other words or phrases, which now become unacceptable because people believe they have racist roots, even though some of these beliefs are plain wrong. Because people believe them, that is enough to ban them.
Here is a brief list, and if anyone is offended I will edit them out.
Picnic - Believed to refer to lynching parties in the American deep south, although this is not true.
A good egg, originally meaning that the person was a good person, but it is now banned because the expression "Egg and Spoon" is believed to be cockney rhyming slang for another racially offensive word
Nitty Gritty - Believed by some to refer to the detritus left behind at the bottom of slave ships.
Incidentally one minister got condemned for using this expression