Strange question yet why?

It's probably just his imagination. I have this friend that whenever he gets excited his hands freak out and start shaking violently, and all this is accompanied by rhythmic swaying forward and back. He's developed the habit of shoving his hands into his pockets when this happens. It was a lot worse when he was younger but as he aged it got better. It's probably similar in this case, it's just something he does and will fade with time. I think everyone has these little quirks about them.