After spending much of today listening to recordings and looking at evidence exhibits and whatnot, I have shifted from it was mutual to Amber is the perpetrator and Johnny is the victim.
That is separate from Johnny being an alcoholic and addict who has trashed rooms at times when his sobriety has lapsed. There were stretches of this relationship that occured during his sobriety (he was sober for over a one year stretch at one point) and the abuse continued - and very one directional.
Additionally, in the recordings where they talk about their issues and their fights and relationship problems, Amber does not bring up his drug / alcohol use - her main issue with him that gets raised repeatedly is that he leaves / walks away / goes to another room or house when the arguments escalate. She takes that as him being a coward and refusing to fight for the marriage. She feels abandoned and stressed and panicky when he leaves when the issue isn't resolved. He tells her he won't stay as she gets physically violent and she agrees she does and says she just loses it if he tries to leave. She tries every tactic to get him to change his response of walking away during the arguments and fights. She pleads, she cries, she taunts, she mocks, she belittles him, she professes her love, she begs him to fight for the marriage by staying and fighting with her. She promises to try to not get physical but says she can only try and can't promise she won't.
mobile.twitter.com/bybyeblackbird/status/1285735012135034893
Watch Part 1 and 2 of this brief video. This is a good example of a common scenario for them - he tries to get away, she follows and then gets physically aggressive when he won't let her be with him.
In this one - He goes into the bathroom to get away. She gets upset and knocks on the door repeatedly. He opens it but doesn't let her in, they are both now pushing on the door from each side. Her toes get scraped by the door and she screams and he lets go of the door. She kicks the door and it hits him in the head. Then she comes in and punches him in the face.