We don't know for sure, but I'd be surprised if the guy was going very fast at the point the bike's rear tire gets leveraged off the ground....for one, the bike never slides accross the center line, plus neither of the two slide very far.
It's not a place where you want to scrimp on having the right gear on, just in case.
Basically, they were very fortunate. If a bike or car had been coming the other direction the lady might be in worse shape.
For those of us who have ridden the Dragon several times, we know that it is like two different rides, depending on which direction one is traveling...heading towards Deal's Gap is what I consider to be going "uphill" most of the way, which presents it's own set of challenges. Going "downhill", or back towards the lookout point and the Lake, is a very different ride, IMO. I prefer the uphill version. Basically, the Dragon is not a place to push your, or your bike's, ability to the ragged edge of control. Neither do you want to poke through it either...finding a nice medium/medium fast cadence where you can get some sort of rhythm going is the ticket through. Going off the side of the road is a very bad thing, as you and the bike will be taking a rather unpleasant ride either thru the air, or into some trees down the side of the mountain.
I used to backpack in the area a lot back in the mid to late 70's and early 80's, and have traveled the road a bunch of times in a cage. Back then, the speed limit was 55mph, if you can believe it. Of course, it was impossible to actually GO 55mph in anything I was driving back then (old VW Bugs and old pickup trucks), but that was the speed limit posted. Deals Gap was just an old raggedy country gas station, and not even open a lot of the time, especially in Winter. My, how things have changed...
Even in July, this is the least amount of clothing I'll wear through there...