It's not the first time we have seen these type of people who can't handle their loss and start blaming casino for their own mistakes but you see in the end they gain nothing out of it as @Hhampuz already cleared it above as this is one of those fake accusations.
It's because many gamblers can't accept that they lost significant amount in gambling and then they will accuse the casino (in general) that they got scam. This is the problem if you risk the money that you can't afford to lose, it's really hard to accept the bad result specially if you're expecting the opposite.
Anyhow, if the accusation has basis and legit, there should be concrete evidence to back up the claim in order to address the issue.