Is it ok for a teacher here to say "ok kids, today we're going to be discussing the terms nigger and paki. All you black and asian kids feel free to leave if you don't like it"?
OK, so this happened in my class just the other day. It was, nominally, a maths lesson. But it started with a pupil saying this.
"Syrians are all Pakis who should just go home."
I didn't feel this could go unchallenged. Many, many other teachers I've met would have just said "you can't say that" and left it there. And the pupil would have felt censored, affronted and carried on as before.
Instead we had a 90 minute discussion on the historical and political context of 'Paki'. Why it's a racist term, why racism is wrong, and why people who feel they should be allowed to use such terms mostly have belief systems that are based on shit, and why and how that shit comes from fear. In other words, we had a long discussion about 'Paki' that challenged in full the original use.
Nobody stood at the front of the class going "Paki, Paki, Paki, Nigger, Nigger, Nigger". But neither did it get ignored.
The result? For the first time in ages I felt I had a valid discussion with someone that actually changed their mind. There were many tangents, particularly over refugees, whereby some pupils actually came round to seeing a different view they could buy into, one that challenged the narrow view they seemingly get from home and probably racist parents. Another tangent was the use by rappers of the term 'nigger' and why context was important here.
None of this would have been possible by censoring the words used. By using the words, explaining their political and cultural context, the power to offend with them was removed. And no kid went away thinking they had been affronted and so with an excuse to carry on as before.
I doubt very much the French teacher stood at the front of the class with his Mohammed cartoon gratuitously taking the piss. I suspect he tried to open up a class discussion, using one of the less offensive cartoons (and yet still got reported for using a naked picture which didn't happen) to illustrate the debate. And I see nothing wrong, or gratuitous, with that.
There were no BAME kids in my class, this is West Wales. But I don't think I'd have acted any differently, particularly, if there were.