Please provide any conflicting Tomasello version, DG, and I will be happy to comment.
Meanwhile, suffice it to say that the normal condition of the Arms (6-A-4) is that the Left Arm is always Straight and the Right Arm is always Bent until the end of the Follow-Through (Both Arms Straight position).
I may be off, but it seems to conflict with Tomasello's idea that "the right arm is always DRIVING down the line". It is toward the end of the "Chapter 2" Tomasello video. I am a little confused by what he is saying here as he appears to contradict himself with this notion. He seems to really favor Swinging over Hitting but then, if the right arm is "always driving down the line", isn't that a Hitting procedure?