While Holder and Breuer may try to pin this on mid-level scapegoats, thsoe very same people may see the writing on the wall and decide being a whistleblower/witness for the prosecution is better than scapegoat.
The longer this goes on the more likely momentum will build from the middle ranks to expose the top tier before their own heads are sent rolling.
"The ultimate authority ... resides in the people alone. ... The advantage of being armed, which the Americans possess over the people of almost every other nation ... forms a barrier against the enterprises of ambition."
- James Madison