winning a parlay bet with an amount of $ 523k is very big, he is really lucky or maybe he is a professional gambler who has knowledge in sports betting such as the NBA.
He could also be a professional punter who got extremely luck since NBA is viewed as an unpredictable sport because of so many upsets when compared to college basketball which is way more predictable in comparison.
x55 isn't really a big multiplier to be frank, but the bet of 10 grand was really high. High risk, high reward basically.