Earlier, with detailed discussion on why the "masterful" bit is a bit exaggerated: https://news.ycombinator.com/item?id=11276798

In short: The strategy is not "win the game", but "exploit the machine to cause a bug".

Seems unfair to say that he only won because there was a bug. You could equally say that the player lost because a bug in his brain caused him to not see the proper move. Stress will cause a lot of players to make mistakes, which in my mind it's a bug of our brain.