Trainer who came out of retirement to beat one of his own fighters

What former fighter who became a manager & trainer, then came out of retirement to fight one of his own fighters after an argument in the 1940's?.

 

Very Good!

Joe Barnum was the son of a gangster in the Al Capone era in 1920s Chicago. As an amateur, he was discovered by Augie DeMille after Barnum knocked out one of DeMille's fighters. He reportedly had 112 wins out of 115 fights as an amateur, winning the Pacific Coast Amateur Championship as a lightweight. His pro record is reportedly 35-24-7 (9).

He became a manager following his boxing career, but made a comeback against his former protege Mario Trigo, after an argument between the two resulted in Trigo punching Barnum. The two met in a ring and Barnum won the decision. Two years later, almost to the day, Trigo returned the favor. The circumstances between Barnum and Trigo was the basis of the movie "Killer Instinct."

Barnum also acted as himself, body doubling in fight scenes and as "Three Fingered" White in "The Untouchables." After his managerial career ended, Barnum became a bail bondsmen and a bodyguard for actresses Marilyn Monroe and Loni Anderson.

His induction into the World Boxing Hall of Fame (1999) was highly controversial, and led to the resignation of several members from the Hall's committee.