Did Vicent D'Onofrio play a double role?

Rating: Null/10 (19 January 2006)

The machine gunner in Hue who confronts Joker (Mad Dog?), was that Vicent D'Onofrio playing a second role? I did not see a credit for said machine gunner.
I was in Vietnam in 1968 with Hotel 2/5 ("two-five") of the 5th Marine Regt, 1st MarDiv but did not take part in the battle of Hue as I was in a military hospital; medevaced two weeks prior to the Tet offensive.
Jacket was what I would call an entertaining dialogue movie but did not serve as a very realistic portrayal of the war in Vietnam. As for the portrayal of the Marines, it was also overcooked but the campy one-liners and dialogue makes it worth a look and a lot of laughs.