When horseback riding with Diana, Rocky says "on your right" as he passes her. He's on her LEFT!
Just FYI: In 1976 I lived in Azusa California with my husband. I saw the real Rocky Dennis when I came out of Stater Brothers Supermarket. He was just standing there in the shopping center as if waiting for someone. I was startled at his appearance and thought he was wearing a mask. We didn't speak. I'm always reminded of that when I see the movie.