From what has been posted by the player and the casino, there is no attempt to defraud, bonus abuse, circumvent limits, etc by the player.
The only reason the player disabled his account originally was to take a break as he may have been gambling too much. Looking at the site, they have no tools for responsible gambling, they do not even mention it anywhere on the site from what I can see, not even a generic statement about how to seek help.
The player also stated his original account was "gone" the casino did not dispute this. So, you can't really claim he is multiaccounting.
The casino also boldy states here in this thread and on their site, they are a No KYC casino, which violates their agreement with providers such as pragmatic and hacksaw.
When you brag about being a no KYC casino, you are going to attract multiaccounters anyways, so this does not seem to be a real concern of yours, unless of course someone wins big and you don't want to pay... or cant pay.
Considering this was a casino launched with some reddit posts (I remember seeing those posts as well) they likely do not have the funds to pay, or simply dont want to.
I know many people in the sportsbook/casino industry in Costa Rica and will be asking around today for more info on who operates it.