I'm so glad this story is still updating! I really hope to see the ending of this someday... only recently found out about timeless scans shutting down and I was surprised it's finally uploading on MangaDex! (the timeless scans website made it a bit hard for me to follow chapter updates since i always forget what i last read, which is why i haven't checked in so long) TY for continuing the story!
Also, it's good to be righteous but at the same time your situation sounds like he made a mistake from the beginning. Especially since he made a point about fairness and favoritism, it's unlikely a professor who has taught the class every year would say a statement like that and not follow through. It's not good to jump into conclusions, especially when it affects your perception of a person. Even if you didn't word it in a way that accused him, you still felt angry and disappointed over an assumption with no proof.