Further analyzing the vid.
I think its save to say that Batman was last time in a fight somewhat around his kindergarden time.
You can clearly see that he was pushed by so many people looking at him and felt he needs to defend Batmans honor lol, he probably thought and daydreamed about this moment for a long time, he kinda charges at the guy a few time or rather semi charges but the better half of his brain tells him that it ain't a good idea.