When targeting Marty 'Monk' Malone, he is identified as a Capo (three stripes), despite him being acknowledged (by himself) as being an outsider - merely an associate. He states that he was never 'made', and therefore never held the rank of Soldier either.
Peter Clemenza does not age nor change his clothes in nearly 20 years (1936-1955).
During the infamous scene of Sollozzo telling Tom Hagen that Don Corleone survived the hit, Sollozzo says "Well, that's bad luck for me, and bad luck for you!". Afterwards, his mouth still moves, but nothing is said.