Behind the scenes
Although he had already worked with Bob Gale and Robert Zemeckis on Used Cars, he was not their first choice for stunt coordinator. Originally they wanted to get Terry Leonard, but he was unavailable. Leonard himself suggested them to get Walter Scott.
He also had a cameo appearance in the first film as the driver of the jeep that Marty holds on to when he is skating his way to school. Scott, in an interview, said that he also cameod in Part II and Part III as the driver of the futuristic Jeep that Marty hooks on to during the hoverboard scene and as conductor on the train when Clara Clayton pulls the cord of the train, respectively. Unfortunately, in Part II and Part III, it is actually difficult to see his face.
His two younger brothers, John-Clay and Ben, are stuntmen too. John-Clay doubled Tom Wilson in Part I and Part II, while Ben doubled Wilson in Part III and played one of the drive-by shooters in Part II according to Bob Gale's commentary on the movie.