are you aware of something about the process I’m not?

At this point the key is to document EVERYTHING and keep those records as sacred as you log book. If it does come up, or more than likely asked in an interview "Have you ever been fired" you whip out the documentation right there an nip it in the bud. Dont give them a chance to form an opinion of you. Im not sure about disputing it on the PRD, but if you can, especially if you can upload the documentation, I would!