Cognitive dissonance isn't about being right, it's about holding a belief contrary to evidence, that belief can easily be modified to fit the circumstances even if it's unnecessary or counter intuitive. JWs are a fantastic example of this. They are told on an almost regular basis that their beliefs were wrong, and then they blindly accept this and go with whatever "new light" is presented. Not only that they view the fact that they WERE wrong, but now have greater insight as being even better than if they had been right all along. They were just told that the generation that saw 1914 wouldn't be alive for armegeddon, but rather a second over lapping generation would be. This makes zero sense, completely invalidates a belief they've had in some form or another for decades and they accept it blindly and willingly. Cognitive dissonance isn't about being 100% right, it's about keeping a belief alive by any means possible. If making crap up makes that belief more palatable, or more special then they will gladly modify that belief and gladly admit that they had previously been mistaken.
Adding an additional resurrection myth ontop of all the other myths that were ascribed to jesus does not some how make cognitive dissonance less likely, nor the kind of mass wishful thinking that you find in pentecostal and other churches today. Does the gentlemen anywhere in his 700 pages address why this particular ancient people was completely immune to any of the psychological phenomenon that are clearly demonstrated by the pentocostals in the video above, or really any number of religious denominations that have "supernatural" experiences that clearly aren't real?