Sometimes, I see apologies stated with similar IP address or matching patterns, which means the sybil check algorithm might be relying on patterns that feels two things are connected because they have similar patterns or have similarities hence it flags them as one or cheater, this is one of the reason why don't use several casino because they could even scam you with such alligation, especially when there is an insane amount of win or huge deposit in your casino wallet/account. I also agree that because they are aware of this vulnerability of their checkers they leave the window open for those who will not find it likely to let go.
Yes I understand that many people get flagged through the geological record but like we discussed if the person can prove this, then the label is removed with apologies. As for big wins, if it’s related to referrals and they suspect irregularities they place a label on the account. But sometimes they freeze withdrawals until you even provide or pass KYC, although I don’t like that but it is said to be for AML