Um...He's kinda forced into it by his uncle. He has no say in the matter so trying to get on good terms is probably a wise decision...
He's tasked by her dad to look after her, so he has the absolute authority to spank her shitty ass in order to guide her into the right path, just like her dad would do. Sometimes you have to take extreme measures against you children for their sake, because that's what would benefit them in the long run, that's what good parenting is, so stop fussing over trivial shit that don't even matter in the face of the bigger problem, which is her anti-social attitude and how bad it could affect her life especially in the future.Why are you defending his actions? No need to run after her like a creepy stalker. It wouldn't be the end of the world if he couldn't walk home with her today. That kind of behavior is just not acceptable.