i used to think it was okay for me to say as i'm disabled. what i noticed, though, is that my doing so 1) communicated to my abled peers that it's okay for them to say as well & 2) made me appear as a pick-me; i was perceived as "one of the good ones."
the r-slur has been causing a very visceral reaction in me for years & i will continue to report each & every instance of it.