Read this story on a nursing student who appears to have been forced out of school for non-objective reasons.
I also had an experience similar. In one clinical, we had a weekly clinical assessment sheet that was a list of characteristics on which we would be graded on a scale of 1-3. You had to get an average of all 2s for the semester to pass clinicals.
One week I had an argument with my instructor. The next week, I received 1s for the neatness of my paperwork even though the paperwork was filled out the same way it always had been. Since I had been receiving 2s on everything throughout the semester, these 1s would have sunk me for the whole class.
I resolved the argument with the instructor and received 3s for neatness on the next assessment list, which gave me an average of 2s for the semester and allowed me to pass. However, the whole thing was a sham.