also it doesn't really help that, at least according to op's wording, they told the kid "[the internet and other broad terms] is wrong" and that's uh, that's a very dumb thing to say, assuming this ever happened at all. it's no wonder the kid (supposedly) assumed the teacher was just wrong.
it is what they said that they said - if that's not what they said *to* the kid it was poorly communicated to us, the readers, and considering their assessment of the kid's disposition toward them (vis a vis their trusted internet sources) it seems like it was poorly communicated to the kid as well
It's clear from the text that she is describing how the interaction must have felt. She is not reporting speech here. There's no poor communication issue going on here, except perhaps on the receiving end.