After I read that post mortem, a clear picture was painted for me. From my point of view, the real problem is the lack of project management. The role of design architect and project manager were totally mixed up. Dan is not only doing the technical stuffs that he was good at (I assume this, but I am an outsider), but also doing things that he was not good at, such as dealing with people and the management side of the project.
I also can feel the tension within the project team(s), not just about personality, more importantly different people were(are) pulling the project to different directions, both Parrot and Perl 6.