They were Club Members and they were, thankfully, uninjured. Here is their description of what happened which is a testament to the strength of the car:
"...................it snapped a 180. We should have broadsided the barrier on the hard shoulder but we didn't. Instead we flipped straight over it, rolled down the embankment and some concrete access steps, taking out the metal handrail and some trees, narrowly missing some electricity boxes and coming to rest upside down on the London bound on slip below."