Very interesting, and quite plausible. He doesn't air all manner of dirty laundry, but he doesn't cast himself as blameless nor the company as evil, so I tend to think that it's probably a relatively accurate version of what happened. As for what happened? In general, the board and he simply grew apart, particularly once his successor started taking the company in a direction he thought unwise. He probably agitated against his successor more than he's admitted, but he didn't completely deny that he spoke out against the new direction on at least several occasions, so I don't think he's really trying to hide the truth, more that he's simply trying to give it a slightly more friendly coloring.