I didn't see Pablo Pozo do anything wrong. He was right to book three times and even though an argument could be held about the red card for Evander Sno, I think he was right too: this wasn't a Cup fight or a Super Clasico, this is the Olympic tournament and one just doesn't step on his opponent's ankle. On purpose or not.
The players played carefully, only after an hour or so the Nigerians tried to actually score, but nothing much happened. The Dutch have a good goalie and his Nigerian colleague wasn't even tested..