Imagine this scenario: you're in an exam. Somebody asks for your help to answer a question. You help them (whisper the answer, slip them a note, whatever). You get caught. You get punished.
That's fine. You're not allowed to help others cheat. You broke the rules. The university is liable to punish you. All of this makes perfect sense so far.
In my experience, it is often the case that this student who, remember, did not cheat on their own exam, often receives a punishment directly related to that exam, i.e. they fail the exam.
This does not seem to make any sense at all. The wrongdoing of the student has nothing to do with their performance on the exam. They did not cheat. Therefore, their exam is a separate thing entirely, and punishing them by failing them seems like an arbitrary thing to do.
Let me give you an example. Say a student punches a teacher. Would this student ever receive a punishment like "oh now you have failed your exam in Abstract Algebra!"?
No. The punishent will be general (suspension, etc), but the exams are not touched.
So, in the above example, why is the student who helped others cheat being punished on their exam, when their exam performance involved no cheating at all? What is the justification for this?