The professor has software available to figure out if the student actually plagiarized and/or failed to cite a source. The professor should make use of it and be ready to present evidence to that effect. If not, the professor is guilt of prejudice by saying the Hispanic student is not capable enough in the English language to properly use “hence.” If that’s the case, I’m sure Suffolk has a Chief Diversity Officer who would be glad to slap the professor’s hand.
That wasn’t what the professor was saying. She was not saying that it wasn’t a Hispanic word, but that wasn’t the way she usually writes her reports.
Maybe the professor did google phrases in her report to see what would come up.
Maybe the student should have used “ergo”.