When I actually went to the Sanlitun embassy area, the closest thing to a riot was a stout Western woman walking her poodle outside the German embassy. Otherwise, it was too hot for anyone to bother go outside and everything was sleepy. The week's worth of rioting on CNN was shot during one day in a well-organized riot properly supervised by the local security officials.
There is no doubt the Chinese were genuinely offended, officials and public alike, but they wouldn't let such a thing cause disorder even though CNN etc. needed the drama.