Applying the word "cheating" to the teacher here is a re-definition of words worthy of Humpty Dumpty. The plain meaning of cheating is to gain an unfair advantage over others in a competition. The teacher administering an exam is not a competitive act on the part of the teacher.

I am deeply disappointed that so many here on Hacker News are resorting to such poor sophistry to defend a very simple, cut and dried case of cheating, and that so many are lending their approval through their up-votes.