Should we be surprised that he knows what he's talking about?
His bazooka and machine gun points are frequently stated by anti-gunners. If they're wrong about them being illegal to own by citizens then 1) Joe's even dumber (and surrounded by equally dumb handlers) than we thought, and 2) these items' legality IS a tacit acknowledgement of the 2nd Amendment guarantee, in the spirit of the Miller opinion (which wasn't well-written) where legal arms under the 2nd Amendment should have a "reasonable relationship to the preservation or efficiency of a well regulated militia (or be) any part of the ordinary military equipment, or that its use could contribute to the common defense."