The central twist of "The Cameraman" hinges on a reel of film shot by a monkey. After bravely filming a violent Tong War in Chinatown, Buster returns to MGM only to be humiliated when it appears he forgot to load film in his camera. Heartbroken, he gives up on his dream. However, it is revealed that the mischievous monkey he befriended had switched the film reels. The 'blank' reel was the unexposed one, and Buster had successfully captured the entire gang war.
The climax occurs during a boat race. Buster is filming when his rival, Harold, and Sally are thrown from their speedboat. Harold cowardly swims to safety, abandoning Sally who is trapped by the circling boat. Buster abandons his camera to dive in and save her. It seems his heroism will go unrecorded. However, the monkey, Josephine, picks up the camera and films the entire rescue. When Buster later submits his Tong War footage to MGM, the reel of the rescue is attached. The boss, Sally, and Harold watch in amazement not only at the incredible Tong War footage but also at the undeniable proof of Buster's bravery and Harold's cowardice. This cinematic evidence vindicates Buster, gets him the job and the girl, and provides a deeply satisfying conclusion where the film-within-the-film becomes the ultimate arbiter of truth.