Why would Thurman be the fall guy? He is just a figurehead DC, and everybody knows it. Firing him would be an insult to the collective intelligence of the fan base.
I think Crossman gets shown the door, and I see a gutting of the roster coming. Perhaps, someone gets brought in as a "czar" consultant type role.
Edit: Sorry, to respond directly to the OP...I could see Rob brought in as a position coach, but surely not as DC.