I'm sure if you did the maths you'd find that the casino winning >$500k from a particular set of games has a high chance of occuring whereas the probability tha

I'm sure if you did the maths you'd find that the casino winning >$500k from a particular set of games has a high chance of occuring whereas the probability that the punter wins 500k legitimately is almost zero. It's like those Minecraft speedruns; you can't necessarily prove it's false (at that point), but if there's a 1/10,000,000,000 chance that an outcome is achieved legitimately, what would you expect them to do?