Teaching of Medical Students to Become Physicians (3): The Middle Finger, Index Finger Trick

As the old story goes:

First-year students at Medical School were receiving their first anatomy class with a real dead human body. They all gathered around the surgery table with the body covered with a white sheet. The professor started the class by telling them, "In medicine, it is necessary to have two important qualities as a doctor: the first is that you can not be disgusted by anything involving the human body". For an example, the professor pulled back the sheet, stuck his finger in the butt of the corpse, withdrew it and stuck it in his mouth. "Go ahead and do the same thing," he told his students. The students freaked out, hesitated for several minutes, but eventually took turns sticking a finger in the butt of the dead body and sucking on it. When everyone finished, the professor looked at them and told them, "The second most important quality is observation. I stuck in my middle finger and sucked on my index finger. Now learn to pay attention."

Would you believe that I actually watched a physician, teaching 2nd year medical students the skill of observation, performing virtually the same deception? However the physician used a plastic cup filled with a yellowish liquid he identified as urine and did the same middle finger, index finger trick and actually got a student up in front of his fellow students to stick in a finger then suck. Then the physician admitted that the container was not filled with urine but actually a potable drink. Everyone laughed.

Though it was all fun and hopefully educational, I always wondered whether this act was really ethical and fair, taking advantage of a vulnerable young medical student.
Am I being overly concerned about this particular way of teaching? Or should our teaching of medical students, including those in the later years on the wards, be tempered by more concern with ethical boundaries? ..Maurice.