I count at least three occasions in that clip where it's completely taken out of context, or where he goes on (as I've seen many of the full clips) to add something else that makes it clear he doesn't mean for people to actually go knocking people out. Half of the clip is him speaking tongue in cheek saying he'll give somebody a smack (haven't we all spoken like that loads of times?; "I'll knock you out in a minute!"), to which his audience, instead of hollering and snarling in agreement, breaks out into laughter as they know he's joking. Look at how the clips are desperately edited together to make him appear like a vicious thug, it's not even half convincing.
I can say, however, that these comments may be taken out of context by some of his rather more hardcore fans and it's perhaps not wise for him to make such jibes or speak in such a jovial manner. But that's Don for you.