That crash in Yvon's video, looks like the guy was saved by a good back to shoulder roll with next to no impact to the helmet.
You may have a problem loading this one but this is a wreck at about 20mph but the real impact is basically a 5ft 10 inch drop to the road. This is a good helmet and it still got destroyed and rung Beagles bells pretty hard.
http://www.jetluge.net/video.html/BeagleBump1.mpg
bob