For me, regardless of what has happened, what hurtful things were said, etc, I decide whether or not to keep up a friendship based on how much I enjoy the friend's company.
If I enjoy their company I can put a lot to one side. People are fallible, and I've said some daft things in my time which with hindsight might have been hurtful, for example, a friend who's husband never has sex with her, I eventually suggested that he might be gay. After that tactless comment I noticed our friendship cooled for a while, but we seem back to being good friends although it took a while.
Another good friend, who we socialise with a lot including husbands, once said some horrible things to me and I was very upset. She came round with flowers after and apologised saying it was jealousy and drink that had made her say those nasty things. I cooled things for a while because I was so hurt but things are once again fine and we have some great times together.
Another time I was sidelined by a very close friend when she developed a new friendship group with another 2 women. I was the unnecessary third wheel and no longer needed as a friend. Things changed over time, we supported her through a divorce and were close again. She's been married to someone else for years and we only exchange Christmas cards, always saying we must meet up this year. She's moved on and although I do miss the friendship and fun times we used to have I accept that's in the past and she has moved on to a new life where we probably don't have much in common any more.
But I do think if you enjoy someone's company and have good times together, a bit like family it's worth forgiving and forgetting as it's quite rare to find friends you really love and enjoy spending time with.
Last weekend, in Rutland, the first statue in Britain of the late Elizabeth II was unveiled.