Plot hole: It makes absolutely no sense that there would be over a dozen cops and soldiers in the lobby of the courthouse and leave only two cops to guard Lecter regardless that he was locked in the makeshift cell. Yes the plot needs a reason for him to easily escape but this still goes against every conceivable protocol for such a dangerous prisoner especially when there were dozens of armed personnel just in the scene alone when he was being transferred from the plane.
Plot hole: When Clarice visits Lecter in his new makeshift cell, she brings his drawings, which were left behind in Baltimore. She tells him how she saw the lambs being killed and heard them screaming, taking one lamb with her when she ran away. As the guards approached his cell after she leaves, the camera pans across the cell, taking in the drawings Clarice had brought, and the top one is a very detailed drawing of Clarice holding a spring lamb. She only told just told Lecter about the lamb, not enough time for him to have done that drawing.