Husband and best friend business dealings go very sour

My husband is a contractor and works by himself with one helper. He has done a lot of good work and to my knowledge only a couple of times have there been problems with his work. We have been married for 8 years, known each other 9. My best friend, who I have known for 20+ years, wanted to upgrade her basement bathroom in preparation to sell her home. She asked my husband to come and give her some advice, good idea. But then they decided he could do the work. I questioned both of them about if this was a good idea? She can be stubborn, cheap, passive aggressive, and wishy washy. He can be, well, an asshole. Oh sure, they said, we can keep it where it needs to be. I said OK, just leave me out of it. Well, from close to the beginning there were issues. I only heard bits and pieces here and there and asked them both not to talk to me about it. Apparently it went way south at some point a month or so ago and then my friend stopped communicating with my husband. Last week, while I was away on vacation, my friend sent me an email saying she is not paying him the balance, the work was not done as agreed to and she is severing her business and personal relationship with him. WHAT? I do not have the details of all the things that were said and done or not said and done. I don't want to know. But I think they need to shake hands and make up for my sake if not other reason. And I've basically told them both that. Complicating this is that my husband did work for another old friend of mine (from before the marriage) about 6 years ago and he is no longer our friend as a result of disagreements about the work. Something similar happened with two other friends of mine from prior to our marriage and although more was involved than work for them, we don't see them anymore either. So I'm sorta reluctant to let this just slip on by. How can either of them, BF and husband, not realize that I am stuck in the middle of this and that they don't have any option, if they care about me at all, to resolve it, make up or get over it and move on? It doesn't matter that my friend has, just weeks ago, moved to another city on the other side of the country. I'd like her to come visit once in a while and stay with us. She's my best friend for crying out loud. I am really upset with both of them for sticking me in this situation. If nothing happens, I end up with a lopsided friendship and a marriage where I'll always remember that my husband was party to messing up my relationship with my best friend. Not to mention I'll be thinking about what my BF has done to my marriage relationship. To me this is just plain not OK behavior on their part. And if they do nothing to fix this its a real indication about how they feel about me. Or am I just crazy? Do I just let this go, don't think about it, just go visit my friend and know she'll never be in my house again. BTW, the work started in July, its now mid-Nov, and this should all have been over and done with in about 5 to 6 weeks. So they've had plenty of time to resolve this. I don't know what to do, and doing nothing is an active choice at this point.

Eh, if this sort of thing keeps happening, then something is wrong with how your husband conducts business. It can't be that every single friend you have is in the wrong. Maybe he doesn't do his best work for people he knows or who know you. Don't recommend any more of your friends to him unless you want to lose them too. Don't get involved - leave them to sort it out and don't discuss it with either of them or take sides. You warned them and they didn't listen. Stay neutral.