"What do you think caused him to want to move back?"
Good question.
I can only speculate, but I think that it was a combination of factors.
1. I think that he was very unhappy with his job and all the pressure that went with it. There were negative influences in his workplace, one of them being the OW. Although I would not credit our marital recovery with his being fired, I do believe that it accelerated the process.
2. When I started to DB seriously.
3. Time.
What astounds me most is the speed in which he is moving from one dimension to another. It's as though he had been invaded by some highly resistant, slow germinating virus that eventually dominated him. The fever finally broke and now the toxins are draining away.
I have no guarantees about where this relationship is headed, but I've decided to flow with the current and see where it takes us.
One other thing that came to mind in reference to your question is that back in the middle of the hurricane, my fear seemed to enlarge the fear he was grappling with, my hopelessness seemed to deepen his sense of hopelessness, my fiery emotions seemed to ignite his kerosene soaked emotions and so on. I think that he is prone to following my lead in some areas, so I have to be careful to set a good example - no matter how much I want to bonk him over the head at times.