The SAS used only 30 to 35 soldiers in the raid, but they estimate that more than 10,000 people claim to have taken part.
The movie was: "Filmed on location in Auckland, New Zealand and London, United Kingdom."
The HK sling system used by the SAS in the film is an older method common for the time period in which the weapon was slung on the strong side and thrown backward as one Commando does when he transitions to his pistol. The preferred method now is to sling the weapon across the weak side which the user can simply release the weapon and it will "shift" to the weak side hip and shoulder to permit easier transition to the handgun and safer handling of the primary as one does not need to sweep it aside, covering friendly forces with the muzzle.