This isn't a piece being braodcast where the use of the word is relevent. The example you gave is utterly irrelivent. Not only that, the show isn't produced by the BBC, they buy it in from a 3rd party production company. The BBC will have very little oversight of what happens on the day to day production of the show, any previous cases at the BBC are utterly irrelivent because it didn't happen at the BBC.Again, that's clearly untrue, as you've already been shown - the BBC has literally upheld the use of the n-word by their staff in the workplace in some incidents.
There are multiple situations where it clearly is acceptable from an actor saying it while playing a character to a newsreader quoting it, etc.. and there are various grey areas where it may break social taboos.
The word has zero place being used in general conversaiton in a professional work environment. Why do you think it is acceptable to start spouting the n-word in general conversation with other in a professional work environment?