Then in the settings area in their account you have a button that makes players hidden from the leaderboard and also (explicitly) not eligible for the bonus.
Do you even tried to play on their site? If you do then you do not really need to ask this questions again because everything has been there already. First, leaderboard is already public sowhat you need to do is just to reveal your transparancy about the site. Second, dice-bet scare that anyone that already have wagered huge amount and just because they do not show the status on public then they can't claim it so it just have to be shown for everyone