Who knows whats the real cause for the fallout....both have tremendous egos.

Is it possible that Elon really really believed they were going to cut trillions of dollars of spending...and he is actually mad about that? (thats the story parroted in press)

If this is true, it sort of aligns with Elons consistent dismissal of bitcoin. He likely just doesn't understand the situation we are in and therefore continually downplays bitcoin's importance.