I think if they know if their casino is illegal in their country, they must ready for something like that. In my country, gambling is prohibited and whoever play and caught, go in jail. I think they just need to follow the rules from the country.
Online gambling is not easy to detect by the government, they continue to operate or partners in other country that are allowed to operate gambling businesses usually business minded people knows what to do in scenarios that they are ban. There are tons of gambling sites now. I wonder if its ban in their country too.
I don't think it's not easy to detect by the government. As long as it can be played or accessed by an average person, it can be detected easily by the government. The possible reason why they can't close it is because it's not registered from them and they don't have the power to close or regulate it.