Good lord! You can't do that! Look, I've been in my fair share of squabbles, but you know the one rule is no sucker punches.
But if one does occur, I believe in the old saying, "an eye for an eye". You bean my teammate? I bean yours. That simple. I don't think the kid who threw the punch should get in real world trouble, maybe some after school detention or clapping erasers, but I also think the kid who wore the punch should get to retaliate without worry as well. Let them duke it out like MEN. That's the type of utopian society I dream of every night when I fall asleep.
I also wonder where the victim of the sucker punch's teammates were at. I expected it to look like a benches-clearing brawl, but nary a teammate came into the scene. Maybe the coaches had them all in line immediately, it's impossible to tell, but I was shocked not to see any backup. I'm sure there is a good reason, and I'm even more sure they won't soon forget it.
Hopefully the kid who got punched has a nice shiner and now gets to take the prettiest girl to the prom and all's well that end's well. Got the win, got the internet on his side, and got the girl. That's the way this should work.