One of the problems here is that Flynn and/or his legal team have done almost nothing to defend him. I’m not a lawyer, but it seems highly irregular for a judge to seek exculpatory information about a defendant that the defense counsel hasn’t even demanded on his behalf.
I'm not so sure that Flynn's defense team was negligent here. It is customary, early in the trial phases, for the Defense to request such exculpatory evidence held by the Prosecution; however, in a case such as this, the DOJ prosecution would block such a request under the pretense of "National Security."
In this case before the bar, it appears to me that the Flynn defense team persisted in their requests and finally convinced the judge that the DOJ rationale was inadequate. In the end, the judge has to overrule the Prosecution and order the information release - which appears to have happened in this matter.
Re: Flynn’s legal team
I have read in several places that Flynn’s son worked in private practice with his Dad and lobbied for Turkey and other countries.
Apparently, the FBI leaned all over Flynn with threatened charges against his son in order to extract maximum cooperation from Flynn Sr.