Quite simply, the RB in your scenario already has unquestionable possession of the ball. The ball touching the plane of the endzone immediately ends the play (as a TD), and nothing that takes place after that instant is live or relevant. With the Jesse James play, because he did not control the ball through the…

“ʰᵉ ʲᵘᵐᵖᵉᵈ ᵃᶰᵈ ʳᵃᶰ...” 

Accuracy is not pedantry.