This is pretty amazing -- a FOIA and a subsequent string of emails between a USA Today reporter and the Department of Justice. Like any email string, you need to go to the end and then read up. Essentially, the DOJ tells the reporter that they have information that undermines the reporter's story but won't tell him what it is. Instead, they threaten to hold it until after the reporter has published, and then give the information to another media outlet in order to embarrass the reporter, all because the reporter is "biased" which in Obama Administration speak means that he is an outlier that does not dutifully fall in line with the Administration's talking points.
My guess is that this is a cheap bluff to prevent a story from being published that the DOJ does not want to see in the public domain. Even if it is not a bluff, this is a horrendous approach to releasing information to the public.