Surveys show that something like 60% (if I recall correctly) of undergrad students admit to cheating. It is hardly surprising that some med students cheat.
I agree with some of the comments above regarding administrations attitudes about cheating. They may say otherwise, but they would prefer not to have to deal with it. Thus, they will make all kinds of lofty statements about honesty but they really don't like to be faced with all the unpleasantness that arises when someone cheats.
I used to be a prof before I went to med school. For a long time, I never really paid any attention to cheating. I never cheated and I imagined that few people did. A few students complained to me about cheating so I started doing things to catch cheaters. For example, I would hand out three versions of an exam and the questions would be identical except for one numerical change. You would find quite a few people with multiple correct answers -- for the wrong version.
It is a pain in the ass when you catch someone. They bitch and moan and you have to go through all kinds of hoopla. I also wasted a lot time soul searching and second guessing. It is no fun to accuse someone of cheating. One person was an honor student and had been admitted to a top 5 law school. It is not pleasant to wreck a young person's career. You wonder, 'Did I make a mistake?'
I did have one funny case. This guy had put down three answers in a row that corresponded to the wrong version (3 in a row was my minimum criteria). The second answer was zero and the third answer was 22. My school had a group that reviewed cheating cases and they supported every case I sent except for this one. They said, "You know Mr. X, the last guy you referred. We have reservations about this one. He is clearly not the brightest bulb in the chandelier and probably isn't smart enough to make this up. " So it turns out that he claims he had written zero because he had no clue (fair enough) and 22 because it was his "lucky number". I said, "Come one, you expect me to buy that?" No! I was born at 2:22 in the morning and I always use it! I can prove it! So he brought in his birth certificate and about 4 sports jerseys all with the number 22 plus multiple team photos with his number 22. I let him off.
But, I will tell you, the admin is generally not happy to hear about cheating. They would rather make speeches.
Personally, I would rather not have grades. Learning is fun. If people need grades for motivation they really don't belong in a university.