Historically, Batista's assassinations and other dirty deeds were done not by the military but by his Bureau for the Repression of Communist Activities (BRAC), which was funded by the CIA. They were, technically, civilians. I'm guessing that they were depicted in Roth's hotel room, just after Buscetta strangled Johnny Ola--"Relax, Senor. Roth, we are taking you to the hospital." That scene was before Batista announced his resignation, so they were still "on the job," not covering their asses. The uniformed military people who barged into Roth's hospital room and killed Buscetta were portrayed that way by FFC, I think, for effect: to demonstrate that Roth had clout with the Cuban government--in other words, "directoral license." This was a rare example of where FFC's fanatical attention to detail slipped up: The officer who killed Buscetta used a revolver; but since the US armed Batista's forces, his standard sidearm (handgun) would have been an auto
loader--a Colt Model 1911, same sidearm used by US military at that time.