Not only is failing to disclose this information to the defendants unethical it is very likely illegal.
Remember the Duke University rape case? Prosecutor not only lost his license to practice law he was convicted for his actions.
If many people were involved = criminal conspiracy. All the agents, prosecutors, etc. Criminal.
What you left out about the Duke Lacrosse case was the democrat prosecuter in question was using the case to launch his campaign for state AG. It was the incumbent democrat AG (Roy Cooper) who did the right thing but only to take out someone who wanted his job.
Mike Nyfong was only convicted of contempt of court and went to jail for one day.
Visions of frogs marching
So was the DOJ/Mueller's team withholding exculpatory evidence from General Flynn's court hearings, but nothing ever happened to them for it, just like nothing will happen to these assholes. The FBI is an unbridled, corrupt group of highly paid politically-motivated government criminals, performing solely to attack those they have deemed as their political enemies, or those they are told to move against by their supervising politically-controlled puppets. That includes grannies, grandpas, and anyone they personally choose to set up, and go after on a whim. They create false narratives, fabricate evidence, withhold exculpatory evidence to cover their slimy backs, and attack with impunity, and are no better than Hitler's Gestapo, or the GDR's Stasi.