In first or second grade I got into an argument with a classmate who insisted that the moon was a star, because "stars shine, and the moon shines. We took the argument to my teacher who told us that my classmate was right, and to go sit down.
It’s possible that I was being obnoxious about it, and she was just trying to avoid embarrassing the girl I was arguing with, but it’s equally possible that my teacher was just that stupid.
She was later fired (well, her contract wasn’t renewed) for failing a few of us in our handwriting unit. It was only after numerous parent/teacher conferences to discuss why we couldn’t learn how to write, and about six months of “they just are not paying attention”, that she remembered that she was teaching that subject during the time period when the advanced readers were in another classroom.
Mine was the teacher that explained the concept of concrete versus abstract by saying the difference was easy: abstract means anything we can’t literally touch with our hands. Like the sun. Really.
Honestly, the way, after she first drops the “Planet Moon” phrase, that he says “The Planet Moon”, in a tone like there’s an implied “wow, did she really just say that?” makes me wonder if either a) he realized he was being a bit of a douche saying it like that so he committed to making himself look stupid too by insisting that it actually was a plent or b) if she put the whammy on him and he thought, “Wait, maybe I’m wrong and it actually IS” a planet.