In his Olympic heat, as the holder of the world record, racing men with times up to 20 seconds slower, he runs at the back of the pack and boxed. At 500m he tries to make a move with two runners to his right. He goes down, bringing one down with him. No one was behind him to trip him. The runners to his right rightfully shouldn't have to give him room to get out of the box. This fall is Ryun's fault. He could have front run or run wide to avoid any contact. It was poor tactics that caused this fall. Like they say in MMA, don't leave the decision in the hands of the judges!