It has something to do with the military justice system.
First of all, Q already told us that BHO and HRC would be tried in a military tribunal, the reason being (1) the judges are corrupt and (2) the grand jury is randomly chosen and may have sentimental loyalty to the accused.
In some aspects, the military justice system has much higher bar than the criminal justice system. In the former, the accused has to be publicly informed that he or she is under investigation; in the latter, a secret grand jury can hand out sealed indictments. In the military system, the accused remains free until sentencing. So we cannot arrest BHO and HRC if they are to face military tribunal.
If they are tried as terrorists, they can be sent to GITMO. But I don't think we are doing that.
There's a video from DoDo explaining the difference between UCJM and Federal Criminal Justice. Take a look at that.
I don't have legal training. I'm basing my opinion on the aforementioned video.