Not everything is a shadowy conspiracy. In fact most things aren't.

I knew it was a grad student!

And he is conveniently dead. And he is a physics major.

There was a case in Stanford back in the 1980s(?) where a grad student killed his advisor with a hammer because the grad student was locked in to his PhD program like forever. And there were two somewhat similar cases at the University of Pennsylvania. A grad student ran through a talk and shot two professors, killing one (and then killed himself?). Another was just a grad student committing suicide, again because of a never-ending PhD work.