Inside Higher Education just posted a troubling article involving the case of Steven Aird, a Biology professor at Norfolk State University (a Historically Black College in Virginia). He was known for being a pretty tough grader, and failed 80% of his students some semesters. What makes it troubling is that the university had a policy that if a student missed more than 20% of the class, he or she could be failed. And in fact, Aird's records showed that the average student in his class missed almost twice that many classes. So, just by following the college's policies, the expected grade in the class should have been an F.
Unfortunately, the university also had an unofficial policy that 70% of their students would get passing grades. So, they ended up crucifying the guy for holding the students to the very standard that the university itself had officially set.
RTWT here, and also read the comments that follow.