Maybe because he played on D for CPJ! Good reason to believe him.
I think he played for Tenuta actually. But I always find his insight on football, and defense in particular very insightful. His breakdowns have always struck me as unbiased, fair minded, and even handed where he will admit what he knows and doesn’t know regarding what play may have been called versus what players actually did.
Doesn’t mean I always agree with him in all things and haven’t on minor stuff recently.
As to the first hand knowledge he obtained...it all depends on the source.
Regardless of the why (multiple whys most certainly including some attributed to him alone also)...CPJ earned a lot of criticism for lack of performance on the D sude during his tenure.
But herein lies the trouble with quoting unnamed sources.