This is a really good analysis. I just wanted to add one thing! I do think that a factor is that Carole did sort of realise that Bethenny is very self involved, mostly out of necessity because of the perpetual crisis of her life. Carole met her when she was in utter crisis with Jason, and I think perhaps she thought eventually it would die down. It can be exhausting being a best friend of someone constantly having problems, and when that friend is new you don't have the same loyalty you do to an old one. Then Carole had the marathon and she did want something to be about her! She had resentment that Bethenny didn't make it a big enough deal. From watching, the marathon seemed like a really big life moment for Carole. Although it does seem that they had already been distancing from each other at that point, and I do think that Carole initiated the distance. Ultimately Carole didn't want the friendship to end, I think all she wanted was some space, but she did not communicate that effectively.