If you've ever tried to play a game with friends and one person starts disregarding the rules, you'll know that it's no fun to play in games where the rules are ignored by some participants. In that case, the only person having fun will be the person ignoring the rules, and it will be at your expense. The other time it can be fun is when the rule is literally "anything goes" or some analog. In that case, everyone understands at the outset what they are getting into. Note, though, that if you've ever tried playing with those kinds of rules (that is, no rules) with kids, they will be the first to yell "no fair! you can't do that!" when you do something that is beyond their conception of rule breaking would normally have been disallowed. Fun requires an even playing field.
The kids in the invitational meet still want to win! Even if it doesn't count in the league annals, the kids know who won and get tremendous joy from winning any heat let alone coming first in an entire event (across heats). Kids under ten are even less likely than older kids to care about the differences between A, B, or invitational meets. The fact that the kids in this particular meet were under ten only decreases the relative differences between this meet and any other meet and increases the relative importance of holding this meet to the same fair competition standards of any other meet. The meet matters to the participants.
We have many years of evidence demonstrating that the right time to raise this particular issue is every time you see it. Turning the question on its head, "When is a wise time to raise the issue?" Is it during an A meet? During the Divisionals meet? or the NVSL wide All-Stars meet? I think most respondents will suggest that the issue be raised with their respective pools and governing leagues and their governing Boards in writing. In principal, I agree with that stance - the best way to address this or any complaint is to raise the complaint in a forum with the lowest stakes possible and with the people who have the authority to make a change. Who of you, who agree that boys should not compete against girls, have actually raised the complaint with NVSL or your pool? If all of you had written to the either Board to address it as soon as it occurred to you, we would not be talking about any of this. My assertion is that most of you have not done "the wisest thing". Moreover, the stakes for this particular issue, are now high enough that it cannot be addressed only by writing to the Board. Speaking up at an invitational meet with the Meet Host was in many ways the lowest stakes opportunity to raise it.
In short, I didn’t make a scene.
I approached the meet officials, first. When I first noticed that a boy was swimming with the girls, I approached the head official - the Referee. That official responded with disbelief. I then approached the Meet Host and our Swim Team Representative with the question “Do we allow boys in girls’ races?” The response was simple and explicit, “No.” I then engaged with the Meet Host for a long time on the rules and we had some casual conversation about my own kids and their performance over the year. The entire thing would have died at this point.
I approached the meet officials a second time. In a later event, the same boy got up to swim with the girls again and this time I recognized it happening before the actual event. I again approached both officials who appeared confused and unsure about what to do.
After exhausting the official options, I approached the registering pool’s team in a frustrated but respectful way. As the swimmers approached the start, it was clear that nothing was going to happen. The pool who registered the swimmer happened to be situated very close to where I was already standing and near the starting side for 25 m events, which this was. As three adult spectators got up to cheer, I turned to them and asked three questions in a normal, though frustrated tone and volume. There was no one else around.
I removed myself from that interaction. After asking the three questions and after hearing no response, I moved away from those spectators and watched the end of the race. After the race was finished, the Meet Host approached me and said, “The other pool would like you to leave the deck.” I complied without incident.