Based on reading that, my guess is that perhaps due to the incline the fancy shmancy computer didn't think to turn on the AWD. Maybe the 5% default power was not enough by itself to spin the rear wheels when they had most of the car's weight on them?
I think the driver should have tried mashing the throttle. Sure, that is a good way to get yourself stuck and buried but I like to see dirt flying in the air.
Oh yeah forgot to mention, Pat if you didn't already know, I've got your infamous lime rock clip on my site too.
I can take it down if it is a problem, but people seem to eat that sort of thing up. I think I may have asked you about this before, but I can't remember for sure.