We didn't know if it could be a scam from the casino or his friend did not meet up to the terms and conditions to receive the bonus. Most time, casinos do have a limit time for a customer to claim there bonus and if they do that late, they bonus must have gone before claiming it.
We need to be aware of the rules that must be taken for us to receive a bonus or else, we might become skeptical of the rules and end up failing to calm at the appropriate time. For me, most bonus should not be in a space of free hours or days before it expires. Enough time suppose to be given.
You don't have a choice because it's a free gift, you're not paying for it therefore the casino giving out the bonus determine when you recieve it and how long it stays. We shouldn't be feeling entitled to things we don't have any reason feeling entitled to.
Also we should make sure we read terms and conditions of a site before using it. If the OP had read the terms of the casino, he would had known that KYC is mandatory procedure one has to complete before they can make withdrawal of large amount.
He should know that casino mightn't request for KYC when you wins small bets but if the wins are big they have to know who they're makings the payment to, incase the authorities comes to question them in the future for money laundering and other crimes.