I think most people will concede that Pistone did an amazing job.
He came in as a complete stranger,established a totally fictitious persona,became a trusted member of Sonny and Lefty's inner circle,and stayed alive for six years.

I would think that he would have been happy to have that as his legacy,but then fame reared it's ugly head. Now all of a sudden,he's Superagent,the Mafia's most hunted man,the destroyer of the Bonannos and most of Organized Crime.

Chalk it up to ego,movie promotion,talk show circuit,whatever.
Bottom line,he lost some of my respect.