XR's are gorgeous machines. I've been able to check a few out up close. I admire the apparent simplicity. To my understanding getting one running competitively is all about attaining the proper "tune," which is far from simple. It's cool that something like that is still racing when the rest of the world is running EFI, ABS, traction control, wheelie control, selectable maps, etc.
That clip reminds me of a highside at the track years ago. Things hurt a little more in your 30's. While I walked away, I was sore for about a year . In my younger years I probably would've been none the worse in a few weeks.
That clip reminds me of the section in "Twist of the Wrist" about how to crash. I will summarize:
1. Know when to get off 3. Bail out off the back 2. If you have lost control, the bike is not your friend. Get away from it. 4. Test your leathers- get on your back and slide. 6. Numbers on lists are irrelevant.