Obviously I shouldn't post in the wee hours of the morning, because in reviewing the thread and my response, I want to clarify:
1. In some states there is an underage drinking exception for religious ceremonies. However, since this case involves beer, I can't imagine what religious ceremony might be involved. (Octoberfest?)
2. In some states, parents can consent to an underage consumption and service of alcohol. Some states require that the consumption be in the presence of the parent, and since this involves some "partying", I would question whether the parents were actually witness