I was studying to be a massage therapist, which is a one year part time course with both anatomy and physiology, and practical exams. All the way through the course I was head of the class both in theory & practical. I aced the written exam, despite there being loads of questions that weren't really that relevant to the course.
Then came the day of the practical. I had already got my own massage couch which happened to be lilac in colour, and all my covers, towels etc matched it - note there was NO restriction on colour, and most of the others had slightly mixes with white & cream. I was the only person with a male "patient", my partner at the time. I know I answered all the questions the examiner asked me correctly while continuing the treatment.
Everyone (including our teacher, who had been in the exam room with us) was shocked to discover that I was the ONLY person in the class to have failed the practical exam. Some of the reasons given were totally invalid, e.g. my trousers (bought from a therapy clothing supplier) apparently would collect lint from towels - whereas the girl wearing VELVET trousers got away with that. And that I was wearing "outdoor" shoes - I was wearing those flat lace up leather "jazz" shoes, the guy on the course had gym shows.
Clearly I passed the retake, and the (different) examiner asked my tutor afterwards what on earth I'd done in the first exam to fail as I was "excellent". On hearing who had been the first examiner, she said that woman was known for failing good students, at least one or two per sitting, "as a lesson to people who were over confident"