Knowing that footpath, you’d struggle to badly injure yourself on it, if he did, unlucky
TBH when I first read which path he came off on, it wasn’t where I was expecting knowing some of the other stuff around there but it’s still a steep path with plenty of roots and rocks, combine this with a bit of speed and I can see how someone could badly injure themselves.
I ride the paths around there almost every week, normally solo, and don’t give it a second thought so it’s a little wake up as to how much injury could be sustained if I did take a tumble.
Hope the guy is okay and makes a speedy recovery.