Just want to chime in a bit here. I don't know any of the details of the specific situation you mention, however I do know a LOT of details of the national arbitration system. While I can understand you are upset due to the impact this situation had on your team, I have some general observations:
I can confirm that the 53rd in EV was due to a "construction violation" that was appealed but rejected.
The ruling was disgusting, relying not on proof but the word of the ES, and was based on an incredibly unclear section of the rules that had gone uncalled all year.
The run was also one of their best all year, and would have resulted in New Trier placing 6th or 7th overall.
The arbitration committee completely missed the ball and the ruling shows a failure in the national arbitration system.
1. The National Event Supervisors (and in particular the EV ones you refer to) don't have any skin in the game with regards to treating one team differently from another (i.e. there is no reason to NOT 'take them at their word').
2. The EV supervisors in question have a LOT of experience with Science Olympiad, and in particular the EV event. They work closely on the rules and help out at the National and State level in a LOT of ways (i.e. they are 'ideal' supervisors that really take their role seriously)
3. Likewise, the National arbitration committee has pretty much the most extensive experience in Science Olympiad as anyone could have. They take their job VERY seriously and focus on nothing but arbitrations during SONT. (i.e. they are 'ideal' arbitrators that don't have any reason to be biased).
4. The arbitrators have an explicit policy of 'erring on the side of the competitors' whenever possible. I've heard them say time and again that they won't use the 'intent' of the rules writers to make a ruling - rather the actual event rules and the general rules. They often do rule against National Event Supervisors as a result of this.
5. We have an FAQ process available throughout the year to help clarify what might be 'incredibly unclear sections of the rules'. The onus is on the competitor to seek clarifications in advance rather than to try to 'sneak something past the supervisors' in a grey area of the rules.
So, if the situation was as you generally describe (an unclear to you section of the rules, which the supervisors ruled one way on, but then you appealed, and the arbitration committee seriously investigated via discussions with both the team coach and the event supervisors), then just because they didn't rule in your favor doesn't mean there was a failure in the system. Rather, the system sounds like it worked exactly as anyone would hope it would: with all available evidence being heard and evaluated against a consistent set of policies by a qualified set of unbiased, engaged arbitrators.