"I don't know what Brandon's motivations are: clearly he wasn't hired back by Anae, maybe there are sour grapes."

Maybe he is just calling things the way he honestly sees them.  Stepping away from the program may have given him some perspective.  Or, it may be that being away from the program means he can't see things as clearly as when he was personally involved.  

Either way, I don't see him taking unfair shots at BYU.  I think he is just honestly describing how he sees things. He may be objectively wrong about his analysis, but I think he is being honest about his assessment.