Pilots are fastidious people. They generally are more risk-averse than the lamest, nose-blowing milquetoast you've ever known. Even the guys who fly stunt planes, and especially the Red Bull's Flying Bull Aeronautics Team pilots, are some of the most calculating and careful people out there. That doesn't mean the pursuit is not without risk. Only an idiot would think that flying dynamic formations at close quarters isn't going to have a hiccup once in a while. Luckily no one was hurt in this terrifying mid-air collision.
Let's face it, stunt flying isn't the safest of sports.