Über Goober A Film About Gamers is a 2004 independent documentary film focusing on people who play role-playing games. The film was directed by Steve Metze and features interviews with Gary Gygax, Peter Adkison, Mike Stackpole and Bob Larson, amongst others. The film has screened at theatres, film festivals, and gaming conventions, winning the award for "Best Film" at Gen Con Indianapolis, 2004.
Interviews with Gary Gygax and Bob Larson have never appeared in a film together.
The context says that the film, Über Goober A Film About Gamers, includes interviews with Gary Gygax and Bob Larson. Therefore, interviews with each person have appeared together in this film. Thus, interviews with Gary Gygax and Bob Larson have definitely appeared in a film together.