I think the referee did a nice job with that game. The two cards that I saw that were handed out to the US were justified. I didn't see the Besler offense, and neither did the referee, but the linesman apparently did, and communicated it being worth the yellow.
[video=youtube_share;qjDaW3VXjnw]http://youtu.be/qjDaW3VXjnw[/video]
At about the 5:40 mark you can see the "yellow card worthy foul" that Besler committed...