I once thrown a blade on a 9X9 APC sport prop on my Diamond Dust too. I made an ungodly noise but no damage. I inspect it before every flight around the blade root for white marks, the sign that there's a problem. If I think it's been bumped on landing I toss it and install another. A pylon prop would be safer but I haven't found one as good as the 9X9 for hook up and acceleration after tight turns.