The main issue I had/have with Duncan was his condescending tone he took towards us fans. He accused us of being incapable of being objective fans. I met Duncan at an SR.com gathering and he's a nice, decent fellow. I bought his post Super Bowl book and enjoyed it. But during that bounty gate period he simply towed the national media and NFL line as if to show he was open-minded about the subject.
As the story played out, yes, SP and Saints got caught after being warned, but the severity of the punishment pointed to the Saints simply being a scapegoat. The so-called evidence that the league had was mostly manufactured and changed as that was revealed. Thankfully, Vilma sued the NFL and they were no longer able to hide behind a CBA stipulation. And I think that Duncan had an ax to grind with Payton, but that is my speculation. If he was gunning for a national gig, that's speculation as well, I guess. Regarding BountyGate, I think he was simply wrong and I think he knows that as well.
And, no, I don't read his work unless portions of it are quoted on this forum.