I've seen Monks pulling on those bells and they (the bell/s) move!
Most gyms have exercise machines where you pull on a grip which is attached to weights. As you pull with both hands (assuming a golf stance and pulling in the direction you would pull a club), both hands/arms are pulling initially.
As the hands/arms get down in "the slot", the right arm converts from pulling to pushing and you'll notice the triceps is used not the biceps. The left can desist from pulling or it can continue.
This is one type of power source. It can also be done more sequentially from the beginning of the downswing (left first then right or even vice versa). Other power sources are there, if you want to use them. Right elbow drive, left elbow, both elbows, left latisimus dorsi, deltoid, pectoralis (uncommon) right hand extension, left arm/wrist rotation, partial right wrist extenison/rotation w/right arm extension, and others. I'd have to think of all the variations. I didn't read TGM to learn this stuff, I worked it out on my OWN!
This isn't theoretical, if someone tells me I can't pull with the left and push with the right, stand back and watch the little white ball...
Brian, right about what? That the right arm can push while the left pulls and/or by itself? If you said that, yes, you would be correct. I don't know why this is controversial.