Because I don't think there were 30 made guys in prison at the time and according to the feds there were less than 30 on the streets.

The feds may not be NASA but I imagine they are capable of doing simple math before issuing press releases.

The feds interviewed him for hundreds if not thousands of hours. I'm sure they wanted to know every single thing he knew, including whether, say, someone like Michael Spilotro was made.