AR 7-1-V:
Team A is in a no-huddle offense and is moving to the line when the ball is made ready for play. Although some players settle into their positions and stop, at least one player never stops and is still moving when the ball is snapped. RULING: Dead-ball foul: Illegal shift that converts to a false start. Team A never satisfied the one-second rule before the snap. Officials should shut the play down and penalize Team A five yards.
As I read this, one or more, not all 11, illegally shifting qualifies the foul to convert to a false start. (Hence my confusion)
Yes, remember that a shift starts when more than one player is in motion and ends when all players have stopped. So, in the A.R., you have "all" players in motion, and then some of them stop, leaving at least one player still moving, so it is still a shift. Now, if all players stop for a second, the false start conversion clause is gone for the down, and if more than one player are then in motion at any one time and the entire team does not stop for a moment (can be less than a second) before the snap, you again have an illegal shift, but it would be a live ball foul.
To break this down:
1. The ball is RFP; team A moves to the line; at least one player remains in motion; ball is snapped -> ball remains dead, team A false start
2. The ball is RFP; team A moves to the line; all players stop for less than one second; ball is snapped -> ball remains dead, team A false start
3. The ball is RFP; team A moves to the line; all players stop for one second; ball is snapped -> legal
4. The ball is RFP; team A moves to the line; all players stop for one second; A88 starts in legal motion; A99 starts in legal motion; A88 stops; ball is snapped -> team A live-ball illegal shift
5. The ball is RFP; team A moves to the line; all players stop for one second; A88 starts in legal motion; A88 stops; A99 starts in legal motion immediately after A88 stopped; ball is snapped -> legal
6. The ball is RFP; team A moves to the line; all players stop for one second; lineman A55 starts in motion; ball is snapped -> team A live-ball illegal motion