Someone's waving their power around, plain and simple.
EDIT: also, this thread is going to be baaaaaad.
I have also seen mental illness lead to behaviors that one could call abusive, gaslighting, etc. The wrong kind of label doesn't get those people where they need to be.
A: maybe you didn't mean it, but when you said _____, I felt it was subtle a slight to ____ or I had a bad experience with that.
B: hmm, you're right I didn't mean it. I will take that into consideration.
Bad reactions include:
A: I'm going to be silently angry at B and write snide things on social media. I will label them with loaded terms.
B: This is outrageous! What has the world come to with this politically correct BS?! Suddenly I have to think about what I say?!