Rosenstein is speaking out because the he knows the direction of the political wind. Now he needs to win favor to escape punishment or at least negotiate a lesser one. Comey is twisting in the wind at this point without much hope.
Comey and Rosenstein both share the same weasely, traitorous nature. It is how they rose to the top in the Swamp. They should hold each other and everyone else like them in contempt.
I agree, although I don’t think anyone, including Rosenstein, gets a “free walk”. More likely, he got a deal for 2-5 instead of 20-25. And his coat and tie life of practicing law is over.