Really? I thought he was just tapping him. I see it now. I didn't even see his friend tapping him like that the first time. I just saw the guy behind him reaching up to tap someone. I assumed it was white shirt but he was telling the other guy "dude, what are you doing? You know white shirt is a crazy. Don't blame me like that."
That's even funnier. The guy behind him was freaking framed.