It would have been different if Pistone actually witnessed a murder. Then they would have had to pull him from undercover right away. But a guy who was half-drunk most of the time bragging about 22 alleged murders? It's just hearsay. The Bureau knew what they were doing there.
Exactly. Devecchio KNEW Scarpa committed the murder and hid the facts. Pistone just "heard" about Lefty, he was never around during a murder or he could have been charged being an agent or not.
