The clock never started! So Heidemann had more than one second to land the winning touch. At the very least, whether she landed it in time was highly in doubt. The match should have continued into another round, but instead Shin was declared the loser. So South Korea’s coach went to the judges.
Despite the clock issue, they ruled that the touch was good and that Heidemann was the victor. South Korea’s coach went off to file a formal appeal.
And Shin A Lam, now in tears, refused to live the piste (the platform that they fence on). In fencing, leaving the piste means that you have officially accepted the judges’ ruling. And seeing as the clock didn’t start, and she should still have a shot at gold, she sat down. It’s the filibuster of fencing.