With hindsight, I'd say don't mess with the copmuter at all once you have a reportable situation.

(But this cause me all sorts of questions as to how staff learns what someone is looking at in the first place. )

Too bad I came in after the answer. My answer was going to have been, seriously, that I would call the American Library Association, first, and my (i.e. your) grad school professors who focused on ethics, second.

This is very tricky, and I imagine you will have even tougher ones in the future.