The body language in the video really tells a bit.

https://www.youtube.com/watch?v=-XzOUDMKr9w

Basically guy makes a joke and the other guy gets offended and tried to get a hand of him. Dude stands his ground and the offended guy tries to put on a tough act and tried to tactically intimidate the dude by having surrounding him with 5 guys.

Tensions rise and they were waiting for a move to happen. Youtuber went full IDGAF mode on them and even answers a voicemail during staredown.
His solid frame singlehandedly intimidated the guys who had a definite advantage in numbers on him and they break it up.

If you're not the type to waste time on a fight or are not fit enough this is the absolute method to use in a eituation like this.