Are you okay with this? So far, they look like scammers. Who knows what they'll do with your documents!
I wouldn't send them anything.
I guess there are no other way left except this. They need to be confirmed that next time the same user will not come to them again and oz.kashi needs his money.
It also looks like the only reason they're willing to resolve this is because of the reputation damage on Bitcointalk, and not because it's the right thing to do.
Or maybe they are learning from their mistakes and trying to correct things as they are moving. Reputation is something that takes years to build. For example: BestChange.