Read the memo-
https://www.documentcloud.org/documents/3711188-Rosenstein-letter-on-Comey-firing.html
Comey did usurp the authority of the DoJ. I figure it was a good thing at the time but it wasn't within the usual bounds of a FBI director. Neither was the situation, however.
Forrest for the trees. The tree is "hurf burf, Comey usurped DoJ authority." The forest is Trump.
At the very least, Rosentstein allowed himself to serve Trump's interest in getting Comey fired, and it damn well wasn't for the reason stated in his memo . . . and Rosenstein, who had considered taping the Big Orange Mistake, should have damn well known "authoring" that memo was not the right overall move in any true pursuit of justice.
Well now seeing that he was a Trump player, he hung around long enough to help Barr with the spin that there was nothing to see. Apparently, his Republican roots seriously has clouded his objectivity and now reputation. I hope he wears it well.
And THIS is strike two with Rosenstein for me. Standing there flanking Barr as Barr did his unmistakably dirty work, lending the legitimacy of his office to this craven gambit, was a craven move of moral and ethical abnegation.
All to what end? To save his pension? When he's still in position to make bank in private practice? Weak and craven. I have no love for Rod Rosenstein.
So, sure, now, having secured his 30 pieces of silver, he may well spill some measure of secrets in Congressional testimony.
Do I think this may in large part be done to burnish his personal rep ex post facto? Why, yes, yes I do.