the origin of the brawl can be traced directly to the rivalry between Olympiacos and Panathinaikos and the recent mess called the Greek League Finals where referees wee dictating results, players were bikkering and spitting each other and fans (or more accurately, hooligans, sensible basketball fans should recognize the Greek League for the joke that it is) were hurling everything they could get their hands on towards the opposing teams' players. It was a matter of time until the results of this vendetta started spilling onto international play as well.
That doesn't explain Krstic's involvement however...not only a coward but an idiot as well as he managed to throw the chair to one of the few players who where trying to protect him. What a pathetic little bitch...