Somebody tell me why Rocco didn't wear a vest on the Roth hit? That never made sense to me...
Rocco probably thought his best chance for escape was to shoot, run like hell, and get lost in the crowd at the airport, so that the FBI guys wouldn't get a clean shot at him. A bulletproof vest of that pre-Kevlar era was very bulky and heavy, and would have slowed down Rocco's attempted escape.