While this is true. Most of the time it bullying does stop after the bully has been punched back (more so than not). It works for the same reasons why most criminals will go for easy victims and not the victims that they think will fight back. What's the point of bullying if someone if your victims are going to hit you in the face every time you try?Just beware for the bullying usually do not stop because you punch/kick the bully badly.
The problem that many "bullying experts" make is that they treat "handling a bully" as being something totally different from "self-defense." The two are the same thing. The reason that bullying has been on the rise is because the schools and "experts" treat them differently. A self-defense mindset would have already calculated that there's a possibility that the friends may jump in, or that the bully may want to get pay back. In a self-defense situation would also focus on the danger that is occurring and not base the present actions to defend based on a future that may never happen. Many times self-defense tactics start before the actual physical assault, and I'm wondering if the OP originally let something that happened in the past slide. Bullies will often test waters before the physical attack occurs. If you can stop them when they are testing the waters then that will go a long way from having to deal with them.
Maybe the OP ignored a comment that the bully made in the past, instead of standing up to him and letting him know verbally, but respectfully that he wasn't going to put up with that crap.