The problem with Victor Rivera seems to be his body language, the way he carries himself. Sure, he sees what happens, whistles, the players stop, but then - when he wants to tell them to take it easy, or to explain why - they turn their backs to him and walk away. This is what I saw quite a few times, Rivera calling a player who is walking away from him and pretends not to hear. I don't know what it is. He is a small fellow, but that shouldn't be a point. His calls were ok, though. Only two yellows: there were a lot of fouls, but no really bad ones.
The USA were good, not individually, but as a team. European. With a careful build-up, with fast combinations, good passing and they used the whole field. At times. There were a lot of shots on goal, a few headers straight at the goal keeper. You'd wonder how many chances the Americans need to score. The Paraguayans played as usual: not great, but deadly anyway.