For some reason I am still part of a Whatsapp group from a muay thai gym that I trained at months ago and coincidentally the coach just posted this same video this morning. He won't stop praising the kids and their parents for making them do this, teaching them how to be tough, never give up because of pain and only stop if you're actually injured. He said "that's how it is in Thailand" and "that's what I teach you, never give up, only if you're injured" and added that this is extra awesome because they're not wearing shinguards. The only thing missing is "Face the pain" playing in the background.
You can't even begin to say everything that's wrong about his take on it but I'd just like to point out that: 1) These kids are most likely not thai and 2) Unless white shirt actually broke his little femur, the other kid "gave up" exactly how this coach claims you should never do.
Not a fan of little kids training with this kind of intensity. They can toughen up plenty playing soccer and wrestling without the head trauma. Taking head shots at this age seems like a terrible idea.