I had a teacher telling us to change a 120 pages long document back and forth three times. The third time we showed her the hardcopies with her revisions and hand waved it away, trying to gaslight saying it wasn't her handwriting(!). Same person saying that the hardcopy we had of the OMG.org specs[1] was wrong (same class, I believe it was a different day) because she wanted Use Case Diagram[2] didn't have arrows denoting directionality (Use Case Diagrams do not have directionality, they just represent interactions). It's one of the two teachers I've ever walked out in the middle of a class in my life.

(The other was one in an engineering thesis orientation class where one of the "teachers" said that "everything that could be invented has already been invented". I walked out immediately, followed by a few other people seconds later after some other comment.)

[1]: http://www.omg.org/spec/ [2]: http://en.wikipedia.org/wiki/Use_Case_Diagram