OK, read closely, your "knee-jerk" ruling will likely not be correct.
Normal scrimmage formation, seven players legally on the LOS. Back A24 is split out wide and clearly off the LOS, then goes in motion toward the formation. For discussion sake, it appears that A24 is trying to set up for a crack-back block. After going in motion for a while, A24 is now on the LOS (breaking the waist of the snapper), HOWEVER, at the snap, A24’s motion was not toward his opponents’ goal line.
What do you have? Illegal motion, illegal formation, something else, nothing ??