Haha. This happened in my Social Studies class in high school. Had this real *itch of a teacher who would mark your answers wrong if the wording even slightly deviated from what she wrote verbatim on the board. Your answer would be correct but it would get marked wrong. Then she would go over the homework in clase and write out the answers on the board and you had to copy them down verbatim and re-submit your homework otherwise you would get incompletes and fail. Alright, so whoop dee doo you just doing a crappy job on the HW and when she writes the answers down in class you get your credit then.
Well we had started to notice certain teachers pets in the class were getting all their answers marked correct. One of the kids getting incompletes borrowed his friend's homework, the teachers pet, and copied half of his answers off it and handed it in. Blatant plagiarism yes, but he did to test a theory. Sure enough, the graded homeworks came back and the kid who copied had several marked wrong that were marked correct on the teachers pet's homework. He got really pissed and called her on it in front of the whole class. It was total ownage and she knew it. Sent him to the principal for copying homework. I doubt she even got so much as a reprimand. Tenured teachers FTL!