Long time reader, first time poster.
This was supposedly Frank Arcadi's street muscle crew at the time of Colisee. Although Gervais was De Vito's mentor, it has recently been reported that De Vito was the one who killed Gervasi, on orders from the Rizzuto's. De Vito continued kicking up to the Rizzuto's right up until the Colisee arrests, as he was caught on camera in the back room of the Cosenza several times by the RCMP. De Vito's hatred for the Rizzuto's mostly came from the fact that he was implicated in Colisee because the Rizzuto's were sloopy enough to allow the back room of their headquarters to be bugged by the cops; the same place where he was required to drop off his kickbacks to the upper echelon. Because of this he had to go on the lam, and during this time his wife murdered their two daughters. This he also blamed on the Rizzutos. I also assume that it's possible he held some resentment towards the Rizzuto's for making him whack his former boss.