Set backs are a part of the journey. Every musician out there has had a performance that was less than stellar. We all work for perfection. We don't always achieve it. Keep working, it's what makes you a better musician AND it's what makes you a better human.
A rating is a one day snap shot. As a judge, I don't know everything your band has endured. I just know what I hear and then compare it to the rubric. In about 6 months, take the recording, listen to it again. (Don't listen to it until then.) Take a copy of the rubric. Circle the description in each line item and see if you agree with the judges. Honestly, I have done this and seen they were right....and that I disagreed. However, this is a very subjective field. Opinions will always vary!