I understand this. But under what pretense would they stop talking to each other ever again. They never expresses and disdain for each other?
There was no need to fall out. It's an open source project. Satoshi had nurtured it virtually alone for a long time. Once enough people were on board then he eased off and disappeared. Maybe Gavin going to see the CIA back in the day gave a him bit of a nudge. That supports the idea that no one knows who he was and he didn't want any prying.