That's not entirely correct. What actually happened was that the button itself had a buffer which accounted for the possibility of people pressing the button, but the press registering 'late'. The buffer was 2 seconds I believe, and because of that even when the button hit zero, you could still press it for two seconds until it actually ends. So, it did hit zero more then once, but the click-buffer never expired until the time it actually ended - All the times before that, an account clicked the button before the click-buffer expired.