I disagree with Mike - in part (we'll see how long THIS lasts!)
I do agree in part.
The actual situation, by the time it gets this far, is not a BOO, it is an illegal substitute (NFHS 3-3-6-g and 2-57-2-c) or illegal player (ASA 4-3-3-I and 4-6-A-1). This is a protest situation, not an appeal situation.
Are you asking about a sequence of "appeals" (using the term informally) wherein the defense tries BOO as their first try? Clearly, the defense knows something is amiss. Who knows why they waited until now to appeal when no one this entire inning has followed the batting order.
But the rule only requires the defense to bring it to the attention of the umpire, not that the defense uses the technically correct words. The illegal player was clearly discovered by the defense, even if they did not know what to call it.
The FLEX who batted is the illegal player and is declared out and DQed (ASA 4-6-4-EFFECT-b) or out and restricted to the bench (NFHS 3-4-2-a). She is considered to have been substituted for #3, illegally, so #3 has left the game. All runners return to their bases at the TOP. #4 is due up. The offense must come up with someone to take the #3 spot in the order - either #3 re-enters or another legal sub enters.
[Edited by Dakota on Mar 9th, 2006 at 05:45 PM]