Fielder setting up in foul territory

Question
My son's team played in their state tournament this past weekend. Their classification is Cal Ripken 12 year old 70 foot. They've played under those rules all season. After playing 2 games in the tournament they were 1-1. The next game had them facing the host team. In the bottom of the third inning the host team got a runner on first. Our first baseman set up to hold the runner on as he had the previous 2 games on the very same field. He was "straddling" the bag with the inside of his left foot touching the first base line side of the bag and the inside of his right foot touching the opposite corner of the bag. An unidentified person pointed this out to the homeplate umpire who promptly told the runner to advance to second. The umpire warned our first baseman but didn't notify our coach or explain to the first baseman what he did wrong. When the same runner stole third our third baseman set up the same way as the first baseman had and the umpire told the runner to advance to home plate. The host team scored 2 runs this way and went on to win 7-0. It had a definite effect on our team. The unidentified man became irritated after listening to other parents question and complain about the call amongst themselves, not toward him. He quickly approached one player's mother with the rule book offering to show her the rule. He never let her actually see the rule and never answered our biggest question. If this was a rule violation why wasn't it called on us the previous 2 games of the tournament? We all left feeling like we had been a victim of some serious "home field" bias. Is there such a rule? Was the situation handled correctly? How come the same umpire from our previous 2 games didn't call this until he was "reminded" about it? Is there an address or forum to file a complaint against this tournament host site?
Thank you for taking the time to read my lengthy question.

Answer
Chris,

It is against the rules for any fielder (other then the catcher) to position themselves in foul territory before the play begins.

The rule is 4.03 in the major league rulebook and the penalty is a balk.

It is somewhat unclear to me based on your description if this is really illegal.  Both feet must be in fair territory (which includes the foul line).

There used to be a player or two in the majors who did cover first base this way and to my knowledge, never had a balk called on them.  But the rule is there.  If I had been the umpire in this situation, I would have warned the player as soon as it was pointed out that this was against the rules (because this is such an obscure rule).  Then, if it persisted, I would call the balk.

As far as an appeal, typically when a play (or game) is over, however it was called stands unless someone filed a protest at that moment.  You can send a letter to the organizers, but at this point, that would just be for your peace of mind.

Hope this helps!

Brian