[O.B.Left]

I really like what fladan is saying. dkerb....Id tell your friend that the arms and the pivot do not travel back as one. The arms , ideally the right arm does its thing while the pivot does its own thing. Together via their individual motions , forces, the Hands, the #3 pressure point, travel the Inclined Plane going back and down. The Pivot provides primarily the IN of three dimensional takeaway's BACK, IN and UP. The Right Elbow arm bending and momentum provide all of the UP.

Try this drill. Go to Top (hands right shoulder high) and freeze. Then rotate your shoulders back to square to the line while holding your hands at Top. See how your Right Hand is out nearer the plane line! See the Right Hand travel isolated from Pivot travel. The Pivot provides so much of the IN! But the Arm motion when isolated is just a little fanning and then a right elbow bending Pick UP! Put it all together and you got the TGM Backswing. Pivot goes around or IN, the Right ARm Fans BACK (or is Fanned by the PIvot in Startup) and Bends UP at the elbow. Two unique Zones (Arms and PIvot) each with their own vector or direction of motion. The #3 pp , the Hands netting out with on plane travel.

It sounds weird but its what we do for most of our movements , naturally. Whats not natural is tying the arms down to the pivot. That would take the arms in the direction the pivot is going . BACK AND IN ...... and most likely too much so.