A competitor was shown wearing a HANS and this review (
http://aussieexotics.com/2008/02/27/...edia-statement) stated nothing was found wrong with Ashley Cooper's HANS.
A side hit, hard but not seemingly harder than many others. Did his belt slip off the yoke? Is this an indication of lesser side impact protection you've mentioned? Other equipment (helmet, seat, belts) failure? None acknowledged in reports and they changed the corner the next year. Would like to see official report, but haven't found one.