The second last tackle could have killed that boy, no joking. If he had landed on his neck, he could have been crippled.
I know nothing about basketball, but in the UK if that had happened in a soccer game the big guys of the team on the receiving end would have taken the fat boy (34) out of the game. They would have told him if he continued "he'd been taken out" and would've followed it up so that the ref would have had to intervene or call the match off.
The team on the receiving end should have reacted IMO. Then the coach. If the coach hadn't reacted, I (parent) would have had a word with the coach. And if he still didn't react I'd have invaded the pitch and got my ass kicked. Rather that than live to regret it.