Here's a good rule to live your life by: Never mouth off to a former boxing world champion unless you are also a former boxing world champion.
It's been a while since Rocky Lockridge earned the WBA super featherweight championship by knocking out Roger Mayweather in the first round, but it looks like he hasn't lost his punch. It's hard to hear what's being said in the video; but judging by the unknown man's body language, he decided it was a good idea to insult Lockridge to his face. A decision the dumbass has to regret making.
We don't know why the man started to launch verbal abuse at Lockridge. Maybe he drank too much of whatever was in that 16oz can he was carrying? Whatever the reason, don't pick a fight with a former world champion. Even if he hasn't fought professionally in several years, even if he's been struggling with health problems, you just shouldn't do it.
Unless, of course, you want to get knocked out in about .2 seconds.