In the course of poking around the CAM literature for source material, I found this interesting study in the journal Chiropractic and Osteopathy: Do chiropractic college faculty understand informed consent: a pilot study, by Dana J. Lawrence and Maria A. Hondras.
Short answer to their question: no.
For those who may not know, informed consent is one of the fundamental principles of modern medical ethics, and it's the cornerstone of human subjects research. The need for guidelines requiring informed consent for all human subjects research was first recognized in the Nuremberg Code, in the wake of the horrific medical experiments conducted by the Nazis. The concept has since been refined in subsequent international agreements and in U.S. federal regulations.
When it comes to research on patients, researchers at medical schools are taught (in mandated educational modules everywhere I've heard of) that absolutely any human subjects research has to have prior approval from their Institutional Review Board (IRB). It's the IRB's responsibility to ensure that informed consent is obtained when appropriate, and only the IRB has the power to determine which studies might be exempt from the informed consent requirement. (Exemptions are usually granted in situations where consent in infeasible and risk is minimal, such as anonymous medical record reviews.) In my experience, this is well-understood by all researchers working with patient populations.
The situation becomes murkier to some when the topic is not medical research per se, but medical education research (say, writing down lists of grades on tests to see if medical students are performing better over time). When do you need consent from the medical students? And when do you need IRB approval? In fact, if you want to share the results of any such research, you have to go to the IRB. This is the first rule of research ethics. You don't collect a single piece of research data without clearing it with the IRB first. And the IRB decides whether you need informed consent from your students. (Default position: yes, you do.)
Lawrence and Hondras showed that this principle was very poorly understood at one chiropractic college (Palmer Center for Chiropractic Research in Iowa). Specifically, they found that among faculty survey respondents (and only 55% of faculty responded at all), there was widespread ignorance of policies for medical education research. To cite just a couple of their numbers, 65% of respondents were unsure whether there were any policies in place at all for student consent in education research. Only 27% of respondents correctly noted that students can decline consent for such research!
Unfortunately, I genuinely don't know how much better the situation would be at a real medical school. Points to the back-crackers for taking the time to research this subject.