I am going to go on a limb here. Tyson, I am only trying to put clues together. I would be crazy to not suspect you as a mafia. Everyone who played Survivor with you knows that you truly have a brain, and use it well.
Does anyone else think it's strange the Tyson 'didn't see' that there was a 3rd mafia. This guy is a genius, you only get that way through reading and adhering to facts in reality. So for him to have not read that message can mean that this was part of his plan to pull him to your side. Who is going to kill the Doctor? Right?
I doubt that anyone here would vote Tyson out of town, because he keeps the game interesting, as we have just seen. But put the clues together. He declares he is the Doctor. Only a mafia member with safety assurance would do such a thing. Put that together with the fact that he is clever enough to make himself seem stupid by not reading an important message posted on this very thread.
I propose that we townspeople suck it up and save our people from Tyson before we lose another, possibly our real Doctor. If Tyson isn't it, then at least we can move forward with knowing the facts. Really not a lot to lose. But I doubt he is the Doctor.