It's funny you mention this as a buddy and me were discussing this same rule last night. He had an interesting scenario working a JV game a week or so ago..
Offensive coach calls time and approaches PU. "We've got a problem. Our next batter got hit by a pitch in last game and now is afraid to get in the batters box. We don't have any more subs."
I swear I'm not making this up!
PU just let the team take an out basically letting the team drop to 8 players. It was the last half inning so he never had to deal with allowing the frightened batter to play defense later but we felt under NFHS she could return and would be considered out of the game one time.
Or I suppose we could just call three penalty strikes for delay and say that she never left the game.