Any casino that has instant deposits without zero confirmation experience this inconvenience before. I remember experiencing it myself accidentally way back when Bitcoin network was flooded by transaction.
I already lost my bankroll on the casino while my Bitcoin deposit transaction is still pending that later on canceled the transaction.
I still redeposit the lose amount on the casino since I like playing in there. But casino in early days offer 0 confirmation instant deposit that’s why they frequently being abused but I don’t remember a casino suffer a huge loss from this method.
Yes, this is the case, in the early years, casinos allowed 0 confirmation and so some gamblers take it and then exploit using double spend.
This might be a good read:
GHash.IO and double-spending against BetCoin Dice.And I do agree that casinos didn't suffer huge losses, it's early days of Bitcoin so no one might not have known this method.