>That would be a very valuable lab, IF students hadn't been explicitly trained in opposite behaviour for a decade by then.

I teach students sometimes. I briefly considered whenever I should give them such important lesson. Very briefly: my job is to teach students my specialty, not give them life lessons. Why would I deal with potentially angry students for doing something that's not obvious I'm allowed to do? Hell, it's not even obvious it that would be a "good" (career advancing) lesson.