Good friend and boyfriend got in a fight

(Sorry if there is spelling mistake english is not my first language) I (F23) have a friend (F23) who was my best friend for a long time, I know her since I was like 3 years old. We had several fight and reconciliation on the long years of friendship that we have. Last year we had a fight wich I don’t haven remember why, but she’s always been a person who take a lot of energy from people, with some mood swing and a lot of anger sometimes. I had to stop the friendship with her several times because I felt like she had always something to argue me about and she just didn’t like who I was because I’ve always try to be the best friend that I can be and be genuinely my kinder self. She went abroad for an internship of 4 months and when she came back from her trip, she look really much change (we have the same group of friend so we see each other a the local bar and stuff). She has been working on herself and was more open minded and a good listener and we reconcile. I introduced her to my fiancé (M25). He’s the love of my life, I have never been treated this good is a gentle beautiful boy and his my life honestly, that’s why we are getting married. He had bias against her because I explained to him many time when I used to be in bad terms with her and how it made me feel. But he put that aside and they got along great. Recently, we were at a party at someone’s house and we wanted to go to the bar, when they ask me who was there I say, my girls and the friend I’m talking about, a boy from the friend group of my fiancé say “Oh no not her she’s problematic etc…” and my fiancé defend her and say she’s change and fun just be open minded. We arrived to the bar everything was fine, then we had a conversation about drinking and driving, because my friend was not okay with the fact that we were going to an other party from the bar and the driver (the sister of my fiancé) had like 6 beers. So the sister defend herself by saying that she wouldn’t put anybody in danger and that it’s rude to assume that, then my fiancé got in the conversation by saying that he have full confidence in his sister and so my friend start repainting like maybe five times “i don’t care” “i don’t care”…. so he push her back and trow the inside of his beer at her and left. I didn’t quite realise what just append. We had our first fight with my fiancé just after that, I was really angry because I feel like it was a violent act and it made me really sad because never in my life I tough I could do something like that. He told me I didn’t control it and that I never did that but my friend had a way of talking and being that push him on the edges and I felt trap. I understand what I meant because I felt that with her too sometimes (not recently but before her internship). But I’m still sad I didn’t show self control or at least apologised when he was less angry. My group of girls are all so disappointed in him because they all really like him and didn’t understand his actions or the lack of excuse he had. The topic of the conversation that start that was also really problematic I was defending his right to drive with a few drink and then got mad. I talk a lot with him about that and he say he regret but only will say sorry for me and not because I fell it. He think the situation will fade and that everything will be okay between him and my group of friends but I know my friend is not the kind of people who let pass by something so disrespectful like that. I don’t know what it says about him or what could I say to make him consider about this kind of action. I also know I should support him in this right and wrong but my heart can’t accept something like that.

TL;DR; : Fiancé (25M) and friend (23F) had a fight, I disprove he’s conduct and don’t know how to make him realise that.