Whoever wins that amount I hope he can post here and verify the winning I'm not comfortable that the owner or representative is the one posting it here, although there is nothing wrong with it.
If the winner have an account here why not, but i don't think he will or so. If the screenshot is posted by OP is the winner's profile history page, he probably a huge bettor, considering he was just lost $7k bet and the win is just a normal win to him. Its just that it was the highest recorded win in the platform as for OP but who knows.
not many high rollers have account here in btctalk. usually, we will hear from high rollers when they need to complain about their withdrawal. that's when they usually find this forum, just to post about their issues. otherwise, they are more than happy to bet without posting here.
high likely, that gambler have lost a lot also. he may have won such amount, but we don't know his losses to this site. but if nothing else, it shows that the site can handle such amount of winnings. some casinos would have trouble paying such gambler if he decides to withdraw this amount of winning.