Cesare Bonventre was a zip who became a Capo at the ridiculously young age of 28!!!!!!

Yes, Tony Mirra was a nasty son of a bitch.
Pistone says he was the most intimidating man he met during his 6 years undercover.
Even other made guys where afraid of Tony so its no suprise that Mirra went into hiding upon the mob learning who Donnie really was - people would have been falling over themselves to whack him (Mirra).
In the end Joey Massino handed the contract to his uncle and he arranged Mirra's murder in Febuary 1982.