Also coming from a victim of abuse, particularly parental abuse?

Yes, he can. Just from this one incident? No. He needs treatment, maybe a separation, continued exposure to his bad behavior and consequences for when he behaves differently. However, he can possibly in fact change. Some people can’t. My mom didn’t for a very long time. It took a longer time for me to forgive her. I still think about some of that behavior. But she did in fact change. And I’m grateful that she did

Nobody is required to accept somebody’s change but people can in fact change

I am deeply sorry you still feel this way from your abuser. I wish I could offer more proper condolences