If Persico is an informant, his case would be the worst kind of publicity for ratting the feds could ever have. Snitching and still having to serve a 139-year prison sentence leading you to die in prison?
Lol who in his right mind would ever rat knowing that this could possibly be the eventual outcome?

"Hey man, we got this nice little proposition for you; you become one of our Top Echelon informants and in return you get a 139-year prison sentence, you're gonna die behind bars, we will lock up your son anyway when we feel like it and on top of that you'll get zero benefits from us. Deal?"

Sorry OP, but I'm with the "I don't buy any of this" crowd.