I saw it happen. He hit the phone with the rock two or three times, and that is all. The fact that you need to embellish what really happened to improve your point sickens me. AT LEASt five times. It's simple, really.
Cell phones are a distraction and they have absolutely no place in a learning institution.
It's about time someone stood up to the ringing-cell phone menace. It really isn't that hard, considering we're all university students now.