If it was a normal relationship
thats sort of the rub aint it

I feel that justifying his actions through his BPD makes a bit better to handle.
i wouldnt so much justify his actions as i would try to understand them, as understanding leads to depersonalizing them. thats very different than excusing, overlooking, or justifying.
I read here that in 2 weeks of NC, the BPD feels the same as we feel at 6 weeks.
i wouldnt translate this literally or apply it to every case. its a brief explanation of object permanence, which a pwBPD lacks - it helps explain the seeming ease with which our partners often move on. there are usually other issues at play, like the fact that we were typically on a different page than our partners, unknown to us.
I just think that after loving, and being loved so much, the BPD explanation gives us a way out.
i found it a genuine blessing to learn about BPD and make some sense of what id been through. these are volatile and loaded relationships. you dont necessarily need "BPD" to create that cocktail, but the wounds, and the process of grief and detaching are typically quite complex and complicated. in that sense, "BPD" can provide a world of understanding, even some comfort.
i have seen (and used) the knowledge of BPD as either a tool or a crutch in recovery. use it wisely.