The message I see a lot of in the UFC is sportsmanship. I see more of it in the UFC than in boxing.
The atheletes (for the most part) show a ton of respect to each other when it is over. You named one of the best examples of that (Hughes vs. Gracie).
It is like anything else though..........heck, just look at the video games today.
Walking away from any type of a fight is usually the best practice.
But that doesn't always work either...look at this kid "just trying to walk away"
http://comegetyousome.com/fights_56.htm
It is the fight at the TOP LEFT