I would also say learning on a full manual camera is a good idea. My wife is a case in point. She started with a digi point and shoot. Then she wanted something better so she got a Contax Aria. That camera has an Av mode and that was all she used. Not a problem because it makes her understand the function of the aperture. But one day she wanted a Rolleiflex. So I gave her one of mine to play with and she was completely confused. "What do I do with this knob?". It was the shutter dial. I explained to her the EV system and how to use sunny 16 but she still had no idea what I was talking about. I think she understands how shutter speed and ISO etc all relate now but she still has no idea how to guess exposure... or rather she hasn't had enough practice. Had she started on a manual camera I am confident she would have understood how everything related to one another. Consiously setting the shutter speed makes you look at it and take into consideration the impact of the speed. Camera shake? Motion blur? In Av mode, I think most beginners would just tend to set the aperture and then take the picture without first looking at the shutter speed.
Now I started with a full auto AF SLR, a Canon EOS. I was determined to learn about photography properly so I took the effort to set the aperture and shutter as I saw fit. In the very beginning though I would break down and use one of the picture modes every now and again. But in the end I persevered and now I know what I am doing.
So in short if your student is not really self disciplined, a manual camera is a good way to give them that little kick in the butt as it were