Why wouldn't a simpler explanation be that the wires produce a radio/electromagnetic wave and that wave gets picked up and induces a current, which is how radio transmitters receivers work?
https://en.wikipedia.org/wiki/Skin_effect
I hope one of the outcomes of this discussion is that someone will tackle explaining how AC power gets from source to load, and what 'earth grounds' have to do with that ... and WHY. The usual hand-wavy 'simple' discussions leave out WAY too much.
could it not also be that some of these students didn't actually learn what was being taught, and just squeaked by with minimum grades to not have to take it again?
To the point, during the time that I was learning fields produced around a wire carrying a current, I was also learning recording studio audio and how hums can be created by running cables in parallel and avoided by crossing them perpendicularly. I had a conversation about it with said physics teacher, and he gave a lecture about it the next day. Yeah, one of those teachers that sets one on a positive course.
Your teacher sounds awesome.