I think manually is a common concept in casinos, there has been a lot of people who have abused the automatic system with the double spending method of nonconfirmation with zero fee etc etc which goes back to the sender because the fee is not enough and it is not getting picked up by the blocks.

It means if casinos let the automated withdraw work, they would see the money coming in and then they would credit the gambler and if they lose they get their money back anyway, if they win they both get their money back plus the wins. Hence the automated system doesn't really work anymore, maybe if the confirmation process takes longer, like takes 3 confirmations to get credits but that would mean gambler can't gamble right away and their gambling hype may die.