With 14 seconds to go, Marcus Smart, who had up until then played as well as he ever has, is waiting for Giannis to shoot the second of two free throws from behind. When Giannis misses, he charges into the lane, stealing an easy rebound from Brown, who had Portis cleanly blocked out. Neither player gets the ball and Portis scores an easy putback.
Then with 11 seconds, Smart gets the inbound and decides to take matters into his own hands, despite the fact that there was plenty of time. Holliday takes the ball away from him in mid air and throws it off him and out of bounds. Bucks ball.
Then with 6 seconds to go, Smart inbounds, then gets the ball back cleanly from Horford. Without any defensive pressure, Smart slightly bobbles the ball at the critical moment. Brown is ahead and open, but Smart can't get the obvious pass off. Holiday gambles, goes for the ball and takes it cleanly.
Game over. Ouch.