Metta World Peace delivered accidently hit his arm on the head of James Harden and thus got a flagrant-two foul and was ejected immediately. Moreover, he may be suspended for one or more games. You can watch the video and find out what happened exactly.
Then, Harden remained motionless on the court. Like everyone thought seeing the event live, it appeared that his elbow on Harden’s head was nothing but an accident. But if you watch the replays more closely, it shows otherwise.