Yamaha R6 Crashes Hard into the Mountain Wall [Video]
The causes of this crash are not known 100% but we can think about the excessive speed, coupled with some dust and maybe gravel on the road. We do not have info on the rider's skills, but a human error cannot be ruled out completely.
One of the youtubers, who's comments appear to indicate he was the rider who fell first, says that that bike was equipped with OEM tires, and this might hint to the lack of grip of new tires, at least until the release agent used for making them is scraped off.
According to the same source, it looks like the chap made it pretty well, one broken rib and two other fractures, but nothing horrible. Ride safe!