Really sorry to hear that, but I'm a betting guy and I say he's going to be fine.
Vomiting is absolutely normal after getting one's bell rung, I'm surprised that none of our MDs here have seen this yet and weighed in. That doesn't mean that it always happens, but it's normal I'm sure. This has been a tough day for him and you, but tomorrow will be better.
Kids fall and get concussions. It's a bummer, but it's just a fact of life. Little boys love to climb and seem to get them more, at least when I was growing up. Consider prayers delivered.
