relax, he's probably the introvert kid like me who was obviously forced to do this so he just went with whatever is the simplest and requires no talking, it's highly likely that this was a consciously made choice by the guy
oh and there's also a guy who's a tree
in my school some more introverted people did volunteer to be trees and other props during plays (although in most cases we got turned down), so i'd say this further proves my point
I had to play rock once with two others. We had to wear trash bags for clothing. And at the stage play, people had to lay onto us like we were pillows with their heads. It was not a fun experience that I will remember forever