You should not blame the acoustics,

From what I gather, it was a theatre, not a performance hall, and the acoustics with have facilitated projection instead of resonance, which isn't a bad thing. Sure you felt like the soloist in the concerto with your inability to hear anyone else. But given the rather surprising grade given, I would say that the acoustics that day wouldn't have been very bad after all if you sat in the audience.

Pity we didn't beat RGS, or we would have a rather strong rebuttal if anyone tried to say we were not as good as them.

Still, they can't exactly say we were exactly worse than them, now can they?