Each team has a scoresheet that they keep score on. So, Team A says, "We put up Leinen!" Team B counters, "We put up Dub." Since the 23 rule is a major component of the APA, it's usually on the top of a captain's mind, especially with a roster full of mid/high players. I'm sure the other team expected a 2 to be thrown and simply waited until the lag to disclose the fact that they broke the handicap limit. The players lag, to find out who will be "on top" on the scoresheet(an inning is completed when the bottom player finishes a turn). Heck, you could pencil everything in on the scoresheet, not bother to tally the numbers and get a surprise when your LO calls you or you see that you got zero'd for that week.
Iirc, our area has a mulligan. You get the match forfeited the first time, the second time you get the night forfeited, I think. Again, since this is a cornerstone of the league, it's pretty rare for people to forget, especially twice. Also, if you throw in a way such that you would not be able to meet the numbers even if all players had been there, I think the entire night is a forfeit(iow, you can't throw your 4 highest players just to take a forfeit when you reach 23 point in 4 matches). It's sort of along the same idea of having relatively close matches. You can't stack a team with 3 strong masters("good" 7's) and a 2 to steamroll 3 matches and maybe get a 4th, without having to play 5 players.
The times I've got to Vegas, I've made sure that I conformed to all rules, because I'm supposed to know them and at that level I expect people to be watching for everything. Fortunately, it was all for singles, so I haven't had to watch for team problems.
If they throw Leinen and you throw Dub, Leinen better be a 9 and Dub a 2. Even then I'm not sure its enough

I'm sorry Chris, I don't mean to come off as another APA a$$hole, but its difficult to believe that you missed the 23 rule by three points...throwing a 5 when you had already played 21. I realize that I'm merely a dumb league hack, but I sure as hell know how many points I'm playing when I throw players. Its been beaten to death here enough, 23 is the big bugaboo.
And after 8 weeks you really aren't a "new" team any more.
I'm really not trying to be an a$$hole, but in this instance you'll probly think I am. (BTW I don't worship the APA. I don't agree with the rule particularly, but its their league that I agreed to play in. So I play by their rules.). As I said before, I think it sucks for you and your team, and it wouldn't have happened against my team.
We aren't all like that. The whole if APA isn't bad because of that one knucklehead.