In a way I am still controlling the a/c, through the student rather than through an autopilot.
I will always log anytime I'm having to use instruments alone to see what the machine is doing as IMC. It doesn't matter whether I'm actually touching the controls or not, since I'm still the a/c commander and responsible for the safe passage of flight. I have no other way to orientate myself and unless I fall asleep (a very real prospect on your 5th time round a hold...) I'm monitoring and controlling the flight by SOLE reference.
If the student mucks it up, I am guiding them by instruction rather than just simply grabbing the controls and correcting the error myself. How is that any different?