Shift/Motion Question

[KEFerrell]

Last weekend I got into a discussion with two ten year veterans about a rule. Being a first year guy and being polite I decided to "yeild to thier experience" and drop the discussion. Upon doing a little more research when I got home I do believe I'm right, Can I get backed up on this, and get a tip on how a Rookie like me can broach it to these guys that they have apparently been seeing things wrong for ten years.

A comes out of the huddle and sets for one second. A2 and A3 go in motion both 5 yards back and away from the opponents goal line. A2 comes set for a second , however A3 does not, continues his motion until the ball is snapped.

I say Illegal shift, they say no flag. Thier logic is that "only one player is in motion and not 'breaking his shoulders to the line'"

7-3-6 says all 11 have to be set after a huddle or shift. At least thats how I read it.