I split up with my exH nearly ten years ago when I was pregnant with DS 2 (now nearly 9) This 'thing' was a big feature of our relationship when we were together. We have found a way to work together raising our 2dc together but it still blows up from time to time away from them and it still drives me mad. It think must be quite common in relationships.
He'll say something to provoke me (quite aggressive or personal) . I'll react (occasionally - I'm much better at not riding to it these days) but if I do, his reaction is allll about my reaction to what he said rather than what he did wrong in the first place.
It's not gaslighting (though he does that too) . It's more me being left with a feeling of 'hang on. You are having a go at me about my reaction to something that you did or said which provoked my reaction' . The whole thing then becomes about my 'unreasonable' reaction in response to something that he said, and what he did in the first place takes a back seat..
Sorry if I am rambling. It doesn't bother me nearly as much as when we were together but it still feels like a tactic on his part.. so I just wondered if there was a name for this.