It can be fun to watch drunk people try to fight bouncers. Somehow they always think they can win, despite the fact that 1) they are usually drunk (or worse) 2) bouncers have training and deal with this stuff all the time and 3) bouncers usually work in teams. Still it doesn't seem to stop morons from having a go.
Observing the clip above there are some great insights on boxing to be studied. Watch it again carefully...
Stance --- bouncer has a very compact guard. Arms in; chin covered; relaxed. He is using a modified Shell or low hand guard stance which suggests he has had some boxing training. His opponent is wild and open.
Defense --- when his opponent throws a wild hook to his head, the bouncer uses a pull, slightly leaning back to avoid the arc. He is also covered partially by a left shoulder roll cover due to the difference in height. The shoulder roll is a very common defensive option from the Shell/low hand guard. He stays relaxed, hands in guard and his feet are firm and solidly planted. From the wild hook, his opponent is left out of position and exposed to the counter.
Counter --- Right to the Point --- bouncer returns a short right, bang on the point of the chin. End of story. The hit is compact and thrown from close to his body, and he delivers it vertically along a straight line, akin to how we hit in hakka kuntao. His feet and hips add to the impact force as he rotates into his return. Landing it on the point of the chin pops his opponent's head straight back causing a whiplash effect -> instant knockout. He follows up and stands over the fallen opponent to make sure the encounter is finished.
That's some nice boxing right there. The other guy will wake up with much more than a hangover, to be sure.