A chain of causes which resulted in the failure of an exam could follow something along these lines:
Suppose a student has been studying about biological processes, most notably the birth process. The student may or may not take notes, and may or may not pay attention in class. However, suppose that this same student's best friend is 9 months pregnant. The entire process has been observed, studied, and each doctor's appointment the student has accompanied her friend. On the way to school one day, the day of the exam, her friend goes into labor and there's no time to get to the hospital. The student and a police officer deliver the baby. The next day the student arrives at school and takes the exam on the birthing process, and fails it miserably. Yes, she's failed it from an academic point of view, but on a grander scale, she's incredibly knowledgeable about the birthing process.