Chin went out. Had a girlfriend. He went out at night time when he knew the regular agents assigned to him were off work. That was another perk of staying low key. Since he always met through intermediaries and was never directly involved with anything, the hot headed night shift agents didn't bother staking him out. He knew that was the time to step out, visit the goomar. Chin was screwing with everyone. It wasn't dignified but it worked. It's the reason the Genovese are are still the "Ivy League" to this day.
He was also caught on a tapped phone talking to his girlfriend in a coherent way in the same time period as his crazy act.
You need a sense of proportion here... Nobody is a ghost, but the Chin obviously put a higher emphasis on trying to evade and deter surveillance and efforts of law enforcement to gather evidence against him and his family. In the meantime you have Gotti who summons the brass of his family to do walk and talks in plain sight during the day, gets taped giving a guy O'connor's address right before he gets shot, etc. There is no denying he was not nearly as shrewd as the Chin to dodge the law.
