Well that is disturbing. I've driven on black ice at night in Idaho at 50+mph and didn't recognize I was until the car wiggled a bit, and I pulled over the physically touch the road and found is slippery as heck. I had a fresh set of Blizzaks though.
It may have been shear fear on their part - hard to say. I've seen plenty of snow-capable 4WD/AWD vehicles in ditches and abandoned on the road - most likely due to drivers that can't use the 'best' tool for the job, properly.