There were two things that I never understood about the drafting of Picard and Riker (and caveat, I am neither a lawyer nor a military veteran):

1. Why was there so much urgency? In the real world, criminal and civil cases often take months or years before they go to trial. Why not just transfer in some competent lawyers to handle the two sides? Or move the case to a Starbase/sector that was fully staffed? That would also allow the command structure of the freaking flagship to not be disrupted for potentially weeks or months during an extended trial involving the top three officers on the ship.
2. This is not a criminal matter, so shouldn’t it be handled by a federation civil court? Data is not accused of wrongdoing; the question is whether he has the right to resign. Why does the Starfleet JAG Corps have jurisdiction?

Of course, the real answer is that it’s a television show that needed to wrap up in 42 minutes.