No one forced the casino on him, he saw the terms that they have the right to request kyc verification if they suspect his activity and I’m sure he’s not new to gambling so he should be aware of this.
While I do agree with you, I would also be frustated if you would need to do KYC for low amounts that you want to withdraw. I have had the same before on some sites and it is not fun but ultimately you comply as it is in their terms, and I think in the long end all casinos will start to do KYC.
It's in the rules of the casino so if this gambler take time to read the ToS then he will not question as to why he's asked to do KYC. Because regardless of the amount, if it's necessary and the casino required you to comply then you have to, this is, if you still want to get your money. Anyway, in the end he got his money already and it is resolved. Though he seem not happy experiencing such because of the value of his deposit.