If anyone wants more info on this but doesn't want to go through his hellstream, he later explains that Chris wanted DD to make a fake game for a finale. He wanted to stage a fake argument with DD&J and the two of them would start playing this fake game. He says that he coded some basic stuff but Chris kept demanding more so they could put it on steam, but eventually just scrapped the whole idea. He then said he gave the source code to Chris and then he started building Bowlbo off it. I think this gives some validity to the people who speculate that the Bowlbo demo getting good reception was a factor in all of this, knowing that he could've got some of that recognition and finally getting that gamedev cred he desperately wants.
It's still pretty insane that he stated that comparing Bowlbo to their games would be like saying he wants to compete with his own game. In a recent interview with a guy who's working with Chris on the game, he said that they've refactored the code multiple times. They did it once so the game runs in a 3D engine instead of being all pre-rendered, and another time to implement a custom developed physics engine, so it's fair to assume that DD's source code has been scrapped completely. Who know though, maybe there's some remnants of his code still in the game. That raises the question, would Chris be down for crediting DD after this kerfuffle even if his involvement at this point is so negligible? I'm expecting DD to try to datamine the game when it releases to look for his code and throw a shitfit for not being credited, so be on the lookout for that in the future.