The last time, my dad spent 24 hours in jail, intimidated the lawyer to get all the charges dropped and get the restraining order lifted. All within the first week.. Then he was angry with a vengeance at everybody. It was worse.
If that same thing happens again this time, he'll probably kill my mom, maybe even some of us.
I hate it's come to this, but it sounds like you need to start a family court evaluation. Court ordered psychologists usually see those intimidation tactics like he used on the lawyer over the restraining order as further evidence of mental instability. It will make you the bad guy in your mom's & brother's eyes but may save her a painful experience.
No good way out of this one. i'm sorry, but i've been there, done that & you have to decide what you can live with. Your mom being mad at you for maybe the rest of her life or getting that phone call about your mom being in the hospital.
For me it wasn't my mom, but an aunt. I Got her husband committed as unsafe to himself & his family Neither she nor her kids (my cousins) ever spoke to me again, but noboby wound up beaten to a bloody pulp. To me, that was a situation I could live with & still look at myself in the mirror.
You've got my number, call if you want to talk.