Every Back to the Future fan knows, Michael J. Fox was not the first actor cast as Marty McFly. The original actor cast was Eric Stoltz. At the time he was an up-and-coming actor with significant buzz. But only a few weeks into filming, director Robert Zemeckis and writer Bob Gale realized something was wrong. Stoltz was a fine dramatic actor, but he wasn't bringing the laughs the film needed. They went to the studio head Sid Sheinberg with a proposition: let them fire Stoltz and replace him with Fox, the actor they wanted in the first place. Sheinberg agreed, but the transition couldn't take place right away. Unknown to Stoltz his days as Marty were numbered.
Recently the cast and crew talked about what it was like to film with Stoltz for Caseen Gaines's book, We Don't Need Roads: The Making of the Back to the Future Trilogy. Here is what they had to say.
Stoltz was very dedicated to the role of Marty McFly, but his extreme Method acting could drive other people up a wall. He demanded, for example, to be called “Marty” at all times, even when he wasn’t shooting. (When co-star Christopher Lloyd was informed that Stoltz would be replaced, he replied, “Well, who’s Eric?” — either jokingly or actually believing that his real name was Marty.) During a scene in which Marty had to push bully Biff (Thomas F. Wilson), Stoltz insisted on using full force with every take, leaving Wilson with bruises.
“Eric is such a different actor, and he could be very difficult,” said Lea Thompson, who says she was “really good friends” with Stoltz. “It was a time when we were emerging from the '70s. All the young actors wanted to be like De Niro and Pacino, which was good in a lot of ways… But it was not the right movie to behave like that. Eric had such an intensity. He saw drama in things. He wasn’t really a comedian, and they needed a comedian.”
But wait, There is more! Eric Stoltz wasn't cut from the film completely. Since they had to reshoot four weeks worth of the movie, production had to move fast. This meant scenes where Marty wasn't seen or was out of frame didn't need reshot. One scene though features the back of Stoltz head and his fist. This is the diner scene when Marty first goes back to 1955 and gets into a fight with Biff. Check out the video below and hear Biff (Thomas F. Wilson) confirm it.
P.S. Could you please release all that footage Universal?