It's obvious you have a personal connection with the kid and your discernment is skewed. If the kid who was punched had been your son, I think you would be seeing things differently. And as far as your first sentence, I'm not even sure what you are talking about.
I wouldn't go as far as saying he deserves no punishment, but high school is different these days. Kids know they can say things these days and almost always get away with it as whoever takes any action will absolutely be crucified.
I remember when I worked in HS athletics it was always the biggest kids who had little shits talk smack to them. They knew the bigger kid couldn't do anything to them so they ran their mouths and let it fuel their Napoleon complex.
I'm not saying kids shouldn't be punished for fighting, but I also wish it could go back to the way where if you were a cocky little shite for no reason someone would shut you up. Way too many kids growing up today who've never been punched in the face.
Until someone starts bringing out weapons or numerous people are involved or kicks/elbows take place when someone goes down nothing serious ever really comes from a fight. Someone gets a little more bruised than the next but a month later they're fine.