Blunt force stopping is way, way, way worse than a car cart wheeling down the back stretch of a superspeedway. . . It's not really close... The car flipping 8 or 10 or 12 times disperses a whole, whole lot of the kinetic energy. Which is then not being applied all at once to a human body.
The G force applied to a person's body going from 160 mph to 0 in less than a tenth of a second is exceptionally high. A basilar skull fracture is a very likely possibility in an event like Dale's or Stanley Smith's. The HANs device addresses the weakest part of a driver's body in regards to a blunt force accident. Interestingly the HANs device actually was talked about and in use at a race in Rockingham all the way back in 96 I believe... I watched that old race and was quite surprised it was in development that early and one of the drivers in the field that day actually was using one.
Darrell Waltrips cart wheeling down the back stretch at Daytona was nothing... Compared to his massive high speed blunt impact into the old dirt berm wall coming off turn 4 in that Daytona 500. Thank goodness Cale Yarborough missed Darrel's car has it went back into the track in the tri oval. Darrell said he did not remember anything for the next few weeks.
And right after Dale's accident DW mentioned that "those are the types of crashes that hurt people." He knew that from his own experiences.