21-15-9 reps for time of
Our body tells our brain that we're experience pain. It is up to us to discern whether this pain is something we should push through, or if it's time to take a break. Sometimes, even us CrossFit types can push it too far. That doesn't mean that we don't stop, there is a time and a place to stop. I know of three people who had to step out of the CrossFit due to injuries while there competing.
Basically if it feels like your muscles are screaming, take a breath, or a few breaths, and push on. If it feels like a bone, tendon, ligament or anything else. Stop & assess what the real problem is. Injuries happen at the gym, just like they do in everyday life. The trick is to listen to your body and make smart decisions so you can get back to whuppin' ass as soon as possible.