I didn't see this anywhere, sorry if its already been posted. But take a look at this link and the video in the article. It talks about how Cal players were faking injuries during their game against Oregon in order to slow them down. The video shows a player get up with ease from a previous play, look to the sideline, and then fall down over the ball with an "injury". I'm sure this happens more often than we think. But a source told the Oregonian that it was a "big part" of their gameplan against Oregon. I'm not sure there is much you can do to prevent it, but it makes watching Oregons amazing offense less exciting.
Oregon football: Fake injuries were part of Cal's game plan, source says | OregonLive.com
Oregon football: Fake injuries were part of Cal's game plan, source says | OregonLive.com