would the casiino pay him or find excuse not to pay and ban his account?
You can win a bet in a reputable casino and still don't get paid a dim, it may be as a result of the player violating the rules, terms and conditions. Go to the reputation board and see accusations some users label against some reputable casino we have here, most often than not, it is as a result of cheating, using two accounts, bonus abuses, and not doing KYC when they request for one. However, some casinos also have the habit of ignoring users withdrawals when they are insolvent especially when players win something that will crash their financial pockets, they used tactics to delay the withdrawals which in my opinion is not good at all.