I think you nailed all the issues pretty well. Carson's biggest bitch was that John hadn't really chosen this for himself -- his father pushed him into it. He just couldn't get past the idea of "John's broken, and she can be fixed" right then. I think eventually, once he calmed down a bit, he started to see John's point, but initially, not so much. As for Rodney saving the day, you're more than welcome to write the story if you like; I'd love to read it.

Thank you for letting me know that the story worked for you.