In those times you speak of the person who got sucker punched isnt a giant douche and actually has friends backing them up even when they are being a dumbshit once in a blue moon. I dont know how many fights you all have been in but other than the bullshit elementary "meet me here after school" fights a guy taping a guy on the shoulder, speaking, and then swinging is about all the warning I have ever got or given. Fighting in the real world isnt the movies.
Act like a asshole + get punched = learn from the lesson.
Act like an asshole + get punched + mommy and daddy call the lawyers to protect your privileged ass = no lesson learned and continuation of assholeness.