Did not see it, but it is all in the gamesmanship that goes on. Personally I do not care for that stuff. Just play your game, and that will speak louder than any tricky stuff.
And definitely do not do what another guy does. That tells me you do not have enough confidence in yourself, so you have to try to put down the other guy to make yourself okay.
But again, that stuff does go on. It was worse in the old days, although back then it was mostly verbal abuse and not gestures or actions so much.