Administrative law is the wild wild west, as we're seeing.

I don't remember precisely, but you're not entitled to due process in the criminal or civil sense of the word—like, the Constitutional sense. What you are entitled to is at least some substantive due process: if your certificate is wrongly denied there are appeals processes that do extend all the way to the civilian court system. It just takes a while and a few rulings by NTSB and a few ALJs to get there.

I'm not saying this is right: this is simply how I understand it to be.