U guys do that since you won a lot, you need to send documents policy???
As I remember, fortunejack's policy about KYC is not about big win. Their KYC is to prevent money laundering activity and terrorism financing, so I think in case of big win and there is no strange activities on the account then they wont ask players for KYC.
I actually never heard that fortunjack asked anyone for documents.
There were some issues in the past regarding bonus system and payments but no one said anything about kyc, and if I recall, I asked live support more than a year ago about this and I am pretty sure they said they are not enforcing kyc.