According to Nicaso and Edwards, Michele "The American" Modica, a former member of the Gambino crime family of New York, who had been deported from both the United States and Canada to his native Italy, outranked Calautti and was assumed to be responsible for Calautti's debts.
Yea I think he paid Modica some of the debt and the money came up missing if I remember right and Modica played dumb about it in hopes Calautti would take the hit. I could be wrong on that though.
I'd say the Rizzuto's definitely got him though if I had to lay a bet on it. He openly bragged about killing Nicolo so I'm betting that's who got him.
As Vito said the debts he did owe wouldn't surprise me either and they chose to kill him during Vito Rizzuto's revenge spree either to make it look like MTL got him
