Holder says he did not mislead Congress over reporter leak probe
cnn.com
cnn.com
Then you testify before congress that you had nothing to do with persecuting journalists simply for doing their jobs.
When congress comes knocking to ask if you've lied or not, you simply say but we had no intention of charging him anyway
You get the best of both worlds. You get all the information you need, you shut down the reporter, you put fear into the other reporters, and you get to deny that you're actually prosecuting reporters for doing their jobs.
Gotta love lawyers.