Well its not unheard of for the student to have a yoke and the instructor to have a set of mole grips.
Although it should both be stick if for nothing else than to stop instructors from getting a wack in the nuts on the full and free check. Although it would be pretty easy to have a floating short stick to replace a yoke. I actually quite like being able to move my legs around without the stick getting in the way on nav ex's.