Ask him to share 3 simple training methodologies for intermediate bodybuilders (the majority of folks listening).
Ask him about recovery from that high-volumne stuff he talks about. When stubbs talked about their workouts, he spoke of brutal all-morning quad workouts and hams in the afternoons, just dozens of sets.
Ask him about his theory on loaded shakes, before, during, and after workouts. How do his guys not vomit?
Ask him to assign a percentage to training, nutrition, and "supplementation" of value that he brings to the equation. Is he more training protocols than anything else (his butal workouts are what we hear about).