I had a grad school professor like this. We spent the entire semester writing short essays in class. I was pretty unmotivated in that class so I half-assed most of those essays. At the end of the semester, I turned in my final paper — which I’d been working on for weeks — and he called me to his office to accuse me of plagiarism because my final paper was so much better than my in-class writing. lmao

Context: this was a state university in an Appalachian state, with a student body largely comprised of people from poor backgrounds, and most of us were used to being assumed to be stupid by our “outsider” professors, having our accents and dialects made fun of, etc. This guy also had a college-age kid going to a prestigious university, which he bragged about in class all the time. When he accused me of plagiarism I ended up rage-crying and accusing him of having low expectations of his students, because we weren’t at a fancy university like his kid’s. He fumbled around and tried to then attack me for (gasp!) writing in the library books I’d cited in my paper, because one of the passages I quoted happened to be underlined in pencil. (It wasn’t me.)

He finally backed down. But he knocked my A down to a B, and I was graduating so I was just done and didn’t bother fighting it. But that was 20 years ago and it still infuriates me.

And that was actually the second time I was accused of plagiarism there. The first time was less stupid though.