These two writers respect each other, have great creative chemistry together, and just signed a major deal as a staffwriting team. Freddie had no success genes. She was used to being a loser, and very comfortable with that. Success threatened her security system. When he ended the collaboration, I felt he made the right choice.
Life is short.
As for Freddie, sadly, she didn't really want to collaborate. She was doing what was best for her ego, not her songs, and resented Tom in her equation from the start. That, I think, was the source of all their collaboration problems. She couldn't see the value he was adding to her package, which was enormous. Tom, on the other hand, will probably be on the Grammy's.