Z? I told you so!

So the grades for my exam on saturday just came out. I did very well in genetics, and pretty well in microbes. The genetics exam was actually my best exam thus far in medical school, which is surprising considering I have always found genetics to be a very difficult subject. When we get our grades, they also tell us the Z score we achieved, which is the number of standard deviations from the mean that you were. Both Z scores were pretty positive, which means that I did significantly better than a lot of my classmates. On the grade distribution plot, however, there are always a few hapless souls who's Z score is in the -2+ range. School policy is that if you have a Z score less than -2, you failed the exam. I don't know how you could study for weeks and get a Z score of -3.2, but according to the chart, it's possible. Perhaps there was a family emergency or something. Alternatively, the person subscribes to the p=MD philosophy, though evidently they missed the part about p= passing your exams....