I've crashed once in training and once on the street, both due to a front wheel lock-up during emergency braking. I cracked a rib & learned the importance of wearing safety gear. I made the decision to keep riding & hone my skills further. I've had several friends crash and a few co-workers as well. I try to be very supportive post crash and avoid judging, whether they screwed up or another motorist caused their pain. Usually after a crash the rider is in shock that it happened to them and have subconscience thoughts of never riding again. They usually come around though to riding again but a few have sold their bikes asap. If they are married the wives usually have a hissyfit and refuse to let the rider ever see the bike again. So I guess in short, be supportive, let the rider come around in his own time, and keep the bike in your garage til they are ready for it.