How can PD stop him from betting?
Sure Stunna can ban the account or even ban the whole IP range after paying him, but Hufflepuff could simply register a new account within a minute using VPN or proxy or Tor (pretty sure he was using such measure since the very beginning).
The only thing PD could do, is to double check the system to find out the bug and fix it.
but such luck should be a big flag that the user is using some kind of exploit.
they should delay the withdraw with the excuse that access the cold wallet is hard due to security measures and put all efforts to find the bug