Unmitigated frustration

The final exam started 25 minutes ago.  I have a student sitting in the back of the room who seems to be extremely interested in what's going on around him...his sight rarely settles on his own paper for more than a matter of seconds.  He did this during the midterm exam, as well.  During the midterm, however, he was apparently concussed and was still under doctor supervision.  I let it slide.  Should his eyes be wandering during this exam as well, two weeks later?

I can't prove he's cheating.  That's where I get the most frustrated.  I don't like being scammed, and I don't like when students do things that are against the Honor Code but when I have no hard proof for it. *groan*

Is it 6:30 yet?