So I didn't see this mentioned.... I realize that we have all 11 set, then one guy goes in motion. If he stays in motion fine. If he stops, however, his next action is what matters, in my opinion. If he stops with his shoulders perpendicular to the LOS, I'm saying he is still in motion, even though he is stopped. If he turns his shoulders to get set, don't most players get set by moving/leaning toward the LOS? If he is still getting set (moving forward) when the snap goes, you've got illegal motion. Though I'm likely talking to the offense before throwing this because of advantage/disadvantage.