all orc mirror is 50% random and 50% skill

Even if that is the case, you have to maximise that 50% skill portion. While dArk may not be as decorated as WhO, his orc mirror strat typically gets him his second hero faster and often cancels the opponents t2 buildings. He lost this time, but he had plenty of opportunity to take that game away from WhO. WhO just played better in the end.