Rafa's off hand during return

I just noticed this: Rafa starts with his off hand near the throat, then he slides it down to near his on hand, then he slides it back up to the throat. I don't think I've ever seen someone do this.

He also picks his butt. Don’t see too many do that either. Oh, and don’t forget the water bottle Chess game. Nervous habits. Dude has OCD.