James Harden during a fast break converted a seriously awesome dunk and the officials decided it did not count, the ball went through the hoop though appears to have come out after it swooped right back to the top of the rim making it appear as if it never dropped into the basket.
The basket was not counted and lead the Rockets to a very frustrated loss, Coach Mike D’Antoni got very heated with the refs and argued with them for a bit until the game resumed.
Harden was able to steal the ball mid-court and rushed to the basket for a uncontested dunk, the refs seemed very confused about the point and ruled it no basket.
Official NBA referee review states:
Although the NBA has agreed the basket should have counted, there currently doesn’t appear to be a solution for the mistake. The Rockets would need to go back to playing against the Spurs to re-create the circumstances and have a different outcome to the game.