The building where the court martial takes place is actually Osgoode Hall in downtown Toronto, the headquarters of the Law Society Of Upper Canada, The ornate fence seen in the exterior shots dates to the early nineteenth century and to this day has the original cattle gates which were put in place to keep cows out. The historic fence survived despite efforts to appropriate the metal for the war effort during World War II.
Captain Hawkes puts his hands in his pockets numerous times in the court room, something that a Marine officer would never do, particularly while walking into the courtroom.