He has his luck playing on that slot machine and won so much money. I wonder how much he already spent before hitting the max-win because I do not think he only spent $5 in one spin and hit the jackpot.
And I doubt there are many people that are earning so much money they can justify to spend so much money in a single game, especially when there are many other gambling games you can play which can give you as much fun with way less money.
They always say that the bigger the risks, the bigger chances of gaining huge winnings. $5 per spin is really huge, especially for small-time bettors and that will cost us a lot which could lead to huge losses but since they're willing to take the risk, their $5 cost has turned into millions. We could say that they're just lucky that day but I think it's their braveness to face the possible risks that brought them that wealth. Not everyone could have that courage though.