Do you have proof of your account balance?
Why, what are you going to do? Pretend you can get his money back for him & charge him for the privelidge of scamming him?
Can you post a screenshot of the email where they ask you for the KYC?
I don't think they often practice this!
They did recently when a guy from the Phillipines used fake docs to try & get his (over 300 bitcoins) winnings.
Cloudbet paid that win so I dont see why they wouldnt here.