Boyfriends dad vs mom

My boyfriend had abusive parents. His dad physically (only when drunk). His mom verbally, mentally, and emotionally(all the time). He forgave his dad but never forgave his mom. I dont think thats fair and every time I ask why he says "Why I chose to forgive my dad and not my mom is my business". Himans his dad had a talk. From what he said when his dad would sober up he would feel awful and try to buy him something to cheer him up. That doesn't make anything right. Something that made him cut off both his parents for a while was something happened with a family friend and when he finally told them about it they called him a liar. His dad and him talked and his dad apologized for everything. He made it sound like his mom never apologized but I found out from his sister nd saw screenshots she sent him a text and DID apologize. I asked him about this and he got ao mad. So apparently his mom did in fact apologize buta month later started saying what happened to him never happened'and told other people my boyfriend was lying. He yelled at me saying "When she publicly denied it ever happened she took that apology back!" I asked did she actually say she was taking it back and he said her calling him a liar again was taking the apology and while his dad hurt him physically, he is a man who is actually sorry and thw situation with the family friend is the only time his mother has ever apologized for anything and she took it back when she started saying he lied again. Idk... How do you guys feel about this?