this is accurate.
but speaking from my own experience, the times i became most hurtful (through shutdown, withdrawal, dismissal, etc.) were the times that i was hurting and/or protecting my ego.
it wasn't intentional—it was a reactive pattern that i hadn't recognized. i wasn't able to be vulnerable with my partner because being vulnerable was punished in my early experiences. and because i was being protective and framing myself as a victim, i wasn't able to give love or receive it.
this doesn't excuse my behavior, but it does offer insight about how hurt people hurt people...
and i think the more malicious people take advantage of this.