So is the idea that the school tells them they could totally do this, and they'd get caught, so as to preempt students from coming up with the idea on their own?
Eh, it sounds like the teacher is just trying to get their class excited about the chemistry. Come for the very pure drugs, stay for the molecular orbital theory and the love of the lab.
That, and because some of the more enterprising students would come up with the idea on their own, so better to depress any such tendency ahead of time than end up with two or three people a year finding out via prison sentences that they weren't quite as smart as they thought they were.