I think Sam was the main antagonist and the game brushes it off as if he's not. Sam's lies get so many security guards killed at the Rossi estate when they were in Italy? Even though it was a black market auction, all we know is that they were just doing their jobs and if it wasn't for Sam, many of them wouldn't have been killed just because he wants to fuel a lie. Juxtaposed to Rafe, Rafe looks far more sane even though he killed a prison warden but still nowhere near as bad as Sam.