Similarly I got accused of plagiarism in ninth grade on a 3 page essay, because I used big words.
This was before the days of the internet. I suppose I could have used something like Encarta, but I don’t even remember if you could copy and paste into ClarisWorks from it, and it was about a fictional book we’d read anyway.
My brother got accused by the same teacher 3 years later. He had an even better vocabulary than me and went on to study theoretical physics.