User blog comment:Zolnir/Flaw in Tournament Setup/@comment-1292715-20160317174508

The best we can assume is the reason there was no referee is because the academy headmasters simply didn't feel there was a need for one. Whether it's to promote trustworthiness to the hunters, or simply situations like these never happened before, we certainly can't fault them for it.

A no hold bar match with a aura monitor and a buzzer to alert the competitors when another is out would make a referee kinda pointless. And there's only so much a referee could do in a fight with almost no rules anyways, and in the incidents with Yang and Penny, there was literal nothing that could've been done due to them being so sudden and unpredictable that there would've been no time to react accordingly. Realistically, that's how useless they would've been in this particular tournament. Maybe after this they'll actually assign one in the future, but who knows?

I don't think it's worth questioning this kind of logic in another world, especially considering everything is happening according to the writers' design, and it'd be stupid to assume they simply overlooked it. Everything is the way it is because the writers made it that way. Simple as that.