I watched the special on TV about it, and they showed the video. Thing is...it was like nothing. The student walked up to get the diploma and some people applauded...it was literally nothing...sounded like 5 people clapping or something. Lasted for all of maybe 3 seconds.
And the families made the point it wasn't even them doing the actions.
Opens the whole thing up to a simple scenario; say one girl doesn't like another girl, all she has to do is tell a couple of her friends ...hey when that girl walks up to get her diploma - clap. There you go, you get that students diploma taken from them.