It should be beneficial for the casino to try to identify errors/problems in the operation of the website or casino software. Because the financial security and profit of the casino directly depend on this. Any sane casino will offer rewards for finding bugs for white-hat hackers and ordinary users, or even organize hackathons.
For sure before a casino is launched, there is what operators always do and that is make sure to test all the system of the casino systems to make sure they are bug-free because any casino that has a bug problem will likely not succeed in terms of revenue generations which is an integral part of the casino operation.
Some casinos even give incentives to expect bug hunters to run several private hunts on their systems before the site goes live, The majority of the casinos that crashed along the way are all doing so because of a lack of proper bug tests and exploitation of the system via the bug or other system failures.
In my opinion, it is impossible to identify 100% of mistakes/bugs in the operation of such a complex site as an online casino. On the testnet, of course, you can simulate certain situations that are close to real ones. But the tester primarily bases his work on previously gained experience (he knows what to look for first, what situations to simulate), but a large number of ordinary casino users can unintentionally create a situation that will lead to a new unidentified mistake. Therefore, bug-bounty campaigns are necessary and important after the launch of an online casino.
If you are some sort of a programmer or having that coding experience and bug expert for you to find out those exploits and holes then it would be that easy but there were people who do able to find out bugs naturally specially to those who are really that making some gambling on the site itself on which they would really be expecting for some bug bounty or rewards on which it would really be that depending on a certain site whether they would really be considering those finds or wouldnt really be giving at all. It would really just vary on a certain individual on which
not all people would really expecting somehow into those finds not unless if its really that a crucial find or exploit or bug then they might be expecting something.