i had an underage drinking ticket also but it hasnt seemed to affect anything. I think if it is not disclosed then it is a problem. If it was disclosed awac would have already known that before the check came back 1 month later.
I repented and joined the Corps and served so if they wanted to hold an underage drinking against me from 6 years ago even after disclosing it, it would be a surprise. I learned from my stupid youth mistake and have gone on to do bigger, better, wiser things.
If all things were considered equal between an applicant and I though I would expect to lose the job because of that incident if it were a tight race.