I bet Robbie was a real dick back in the day and decided to take all the royalties from the songs. Who knows what really happened though? There's always two sides to the story. And I hope one of these days Robertson and Helm can bury the hatchet because regardless of their personal differences, they made great music together. I mean, I wouldn't really want a Band reunion tour with only three guys but it'd still be good if they were on good terms.
That being said, I happen to think Robbie's a great guitar player although being the cokehead that he was (or is) his ego was (and could still be) huge. And towards them turning his mike off, well who can't laugh at that haha.