My opinion is that there might have been a contract right after the infiltration was revealed. It was done in the heat of a moment and i would'nt completely exclude the possibility that some bosses got together and decided they should do something about it as it was a massive embarassement. I don't believe there was any money as Mob contracts never involved money. Nobody gets paid for killing someone in the mob (you get made, you get connections or easier access to a business but not cash unless it's a murder for hire situation).

I don't remember the source but i have read somewhere in a Gotti Book that, at some point, Castellano pushed to remove the contract. Gotti was supposedly mad about it since he was close to Sonny Black and Joey Massino. I don't think it's highly credible but i would say that's the only mention of a contract on Pistone that i know of.