Some people can in fact use this word. This sentence reads as if you know the person really shouldn’t be using it because you know their race isn’t allowed to, however, there is indeed a race that is allowed to and the original poster could very well belong to that.
The fact that you can’t understand how this could have been posted by one person uncensored, then screencapped by a second, then censored by a third, or even fourth person, fifth person, etc, is frankly just icing on the cake.