@Serapheid: It seemed that way too me. I'm also not from the U.S. What I saw was a human being, that those A-rank hunters couldn't subdue. But even though that guy does look like a human, at least to me, they drew the conclusion he must be a human type monster. He didn't speak english, fair enough, but it's either he at least tried to communicate or the hunters attacked on spot before he had a chance to do so. Those hunters also noticed, that the dungeon was spot clean. All of that gave the impression those hunters have only have a brain.
I give to them, that there might be human type monsters, maybe some dungeons only contain a boss and that the guy emitted a huge loads of magical energy, but why did they then attack first? That's a good strategy if you have a chance of winning. Wouldn't be ordering a retreat the better decision? They are A-ranked adventurers, they should know that. And I'm sure a battle would have ended right there.
We didn't see anything of that encounter and there is a chance, that everything might have lead up to what we saw. But the only thing we did see, have been beaten up and fainted adventurers and one, that screams in total panic, as one of the closest explanations escaped him, that this somehow is a fellow hunter. And this does primarily evoke the impressions of stupidity and cowardliness. And that in turn is no new way to show "Hey! So superior!" It just leaves a bad after taste. But hey, that's just MHO.