her feedback was delayed/messed up. Similar to when famous singers mess up on their live 'lip syncs" and get made fun of.
Still, no excuse. How could she not know it was that bad? She could have pulled the ear piece out. Or waved at the crowd and said, "Something is wrong with my mic, everybody join in!" and just had the crowd sing the anthem.
Instead, she hung with it to the bitter end. Not sure if I should admire her for her courage or laugh at her.
Or she really was drunk...