Character mistake: When Barnes is trying to describe what he saw, he awkwardly describes "something like a flash of light." A Secret Service agent would know that he had seen the muzzle flash from the gunshots. (00:17:40)
Character mistake: After Barnes rescues the President, he radios in his location as "seven blocks east of the plaza." This is meaningless on the limited-access highway where they are located. Barnes has an excellent grasp of the local geography and would give their precise location with specific landmarks. (01:21:20)
Character mistake: At the end of the film, the newscaster comments that the lone assassin has been killed, but the ticker beneath him reads "Lone assassin arrested."
Character mistake: At the end of the movie the reporter says the lone assassin was shot and killed but the banner at the bottom says the lone assassin was arrested.
Character mistake: While talking to President Ashton, Phil McCollough comments, "We're looking for five people out of six million." Salamanca's population is only about 160,000.
Chosen answer: It's not stated in the film, but if I had to make an educated guess I'd say his job is to make sure the news channel doesn't get any footage of any of the terrorist agents or the window the shots come from.