[mikesears]

The rulebook seems to address 2 situations.

(1) A player knows he is supposed to leave the field and tries to do so.

(2) A player does not know he is supposed to leave the field and is positioned in the formation.

What we have in the play in question is the middle ground--a player who is unsure if he is to be out there. If we let the snap occur, we are in danger of having to call the bigger foul. If we kill before the snap, we might get a coach upset because he could have called a timeout to fix the problem.

I am of the opinion that we should kill the play. The penalty is for failure of a replaced player to leave the field immediately. If he is waffling, he isn't leaving immediately.