1. Assessment is only a small part of teaching. Often the smallest.
2. The pedagogical intervention depends heavily on whether the student is cheating or just FAR below grade-level.
3. the student likely won't be truthful.
4. Even if we assume the student will tell the truth, if they aren't using an LLM and you accuse them of doing so it's going to crush the student and make teaching that pupil close to impossible.