this is amusing to me. What makes you think he's not loading both scaps? He has some of the best scap loading I've ever seen.
granted, it is somewhat of an A-symmetrical loading, but it's there. All, I repeat ALL high level throwers scap load. It's foolish to think someone can throw 95 mph (and in Wagner's case 102 mph) without doing so, especially given his smallish stature (5'10").