This topic is constantly being resurrected because one group of individuals feel that people should fight with their fists before deadly force is presented/applied in a self-defense situation. Lets examine the facts:
Proponents of the above video claim that this is an ideal situation as to how a situation can be handled via hand-to-hand combat. What these individuals are failing to mention is that the individual who knocked the punk ass idiot out actually is in the advantageous position in this instance, due to the following:
a) The defender is bigger than the aggressor. Because of his height advantage, and the fact that his arms are either the same size or slightly longer than the aggressor, he now has a mechanical / physiological advantage in that he can generate far more force in a a far more efficient manner, all while maintaining adequate distance to make the aggressors attacks ineffective. Let's assume the aggressor in this video is 5'8, and the defender is 5'10. What would have happened if the defender was 5'6? What would have happened if it was one of the females instead of this male? This changes the dynamic of the whole situation, and in fact changes the perception of threat to the individual, should the roles have been different, and the defender been a smaller, weaker individual compared to the aggressor.
b) The aggressor is not only drunk, but his motor skills are severely impaired. Look at how he staggers around the beach, his speech is sporadic, and how physically impaired he was to throw the punch and respond the the counter-attack of the defender. Alcohol is a depressant, meaning that it suppresses many of the physiological and neurological functions of the body/brain, thus 'impairing' them. Its easy to beat a guy up who is drunk off his ass and falling all over the place, but what would have happened if the individual had instead been using some type of stimulant like an amphetamine? People on stimulants normally aren't staggering all over the place, as these drugs actually promote the production of adrenaline and dopamine in the system, resulting in a higher threshold for pain, better command of motor skills (in terms of attack), and the ability to sustain a prolonged attack than a drunk person due to the decreased response of fatigue.
Self-defense is defined as the ability to neutralize a threat effectively and efficiently, all while reducing the possibility of bodily injury or harm to oneself or other individuals. If someone has the ability to say, 'stop or you will be shot' vs having to risk potential bodily harm by getting into a fist fight, which is more effective and efficient and reducing the risk of bodily injury to the defender, all while neutralizing the threat? And unarmed combat is only necessary because of the following: either the laws of the area do not allow one to defend themselves with weapons, or unarmed combat is taught as an alternative form of self-defense in the event that the weapon is unavailable to be used at the precise moment. In the latter case, either the threat is neutralized because the individual will not have a chance to obtain his/her weapon at all, or it allows the individual to gain the advantageous position in which to obtain his/her weapon and further neutralize the threat without further unnecessary risk to his/herself.
I will agree with bubba808 on the fact of walking away. But if there is no ability to walk away, then I am neutralizing the threat in the most effective means possible.