Also, too big Kelly criterion does not necessarily lead to casino's loss.
Usually, to attack a such buggy casino, attacker will need much more money than a casino's bankroll. With no any garanties.
I think, it's more risky for attacker, than for a casino.
please explain in numbers what is "too big Kelly Criterion"? there are KC numbers which will ruin the casino as RHavar explained very well
2x kelly will have no growth or decline in the bankroll on average long term (although incredibly wild swings in bankroll are expected). Anything greater than 2x kelly, and you can expect bankroll to decline; the larger the kelly, the faster the decline.