This was the hot topic from the past few days. The guy was sure lucky, there are rumors that it was the banker who bet 51 btc since the max limit for betting in sports was only 10 btc (not sure though). Whatever the truth, congratulations to that guy. He rocks! My bets in sports were lames so I really admire the guy.
So yeah, IMO this doesn't really pass the sniff test. Not saying house put the bet in their system to create PR, but for a new sportsbook to take a 30+btc win bet on a single line (not a parlay even), is highly unusual. Especially considering they must have a very shallow data pool in which to qualify that player for higher limits. Usually you get higher limits by proving that you will make profit for the betting site. I don't see how they could know that about any of their sports players at the moment ...
But they're not brand new in the crypto gambling world and they must have a big bankroll from their casino and dice, so who knows, maybe they were crazy enough to take that bet.