I've serious questions about immunity for Huma. While Hillary's primary interest in the private server was defined by criminality, suspicions about Huma should be defined by espionage.
All those "Classified" and "Top Secret" items on the server could have been selected by Muslim Brotherhood agent Huma for the 'Hood's hackers to access.
Huma still has Saudi connections. That may stymie anything other than immunity and testimony.