The first weekend of games brought at least two potential uses of the "fake injury" tactic, whereby a player gets directions from the sideline to intentionally slow down the opposing offense. The first was the UGA v. Clemson. The evidence is pretty clear: http://www.youtube.com/watch?v=2gKCBKwgkNE&feature=youtu.be. The second was the Cal v. Northwestern game, which was obvious to anyone who watched it. Northwestern went down with at least 7-8 "injuries," almost all of which coincided with Cal first downs.
With the increasing use of uptempo spread concepts, fake injuries are becoming more common. The question is, how can officials stop this? Is there really any way to reliably sniff out this kind of impropriety? I'm curious to know what people think about this.