Learn something every day. Power woodcarving....wow - the very idea of that smells of danger that even ruffles my feathers.
I own 5 electric angle grinders and 10 small air grinders. Have used them for hundreds of hours grinding what they were meant for - metal or stone. Changing the premise of the tool with a chainsaw style blade into a soft material like wood brings with it many dangers that don't exist with metal grinding.
If you misplace the grinding wheel location quadrant while grinding metal, you will scuff another spot on the surface and the sparks/material will fly into a different direction, but nothing severe will happen otherwise. I also prefer using the edge of the wheel for small, accurate material removal. Danger with that is the wheel shattering or cracking, but that is very uncommon with some semblance of control and feel for what you're doing.
It is customary in the automotive world to place yourself away from the danger zone of any tool - both the outfeed of the grinder (having hot metal grinding dust fired into your exposed skin can cause blood poisoning....ask me how I know this lol), as well as staying clear of the area when/if the tool should break, wander or turn around.
Without question, our friend in the video was standing in the wrong location, he should have turned the workpiece around and stood behind, not in front of the tool. Basic mistake IMHO, and I see no redeeming explanation for actually doing this in any way shape or form. I bet the manufacturer of the blade and tool would have something to say about using either on anything but a convex or flat surface. Total fail waiting to happen.
Secondly, the very idea of using anything but the edge or top 1/4" of a cutting blade like that is suicide waiting to happen. If you insist on woodcarving, use a real chainsaw - the tip does a great job of carving out wood in a similar manner without the danger, the 2 stroke oil scent may drive the wife crazy, unless you use Klotz, which smells like laundry detergent, lol.
a 16 year old hooligan stuck in a 55 year old's carcass