Heads will be rolling over this one.
Even if the recruit comes out of this coma, he may be forever compromised with a ‘minor’ brain injury. There may be a medical discharge coming up. No doubt the other guy feels terrible about this. The risk is always present when you smack somebody hard enough to knock them off balance. Even for someone young and in top physical condition.
The covering on your brain is very delicate and even a car wreck of around 20-25MPH can cause a serious brain bleed if you are not wearing a seatbelt.
You don’t even need to be smacked.
I had a stroke when I was 31. 2 years out of the service and in good shape.