This odd provision seems arbitrary until you see it from the point of view of the authors. It underscores their paranoia for judges, such that simple proximity to a "judicial body" somehow threatens the functioning of the Special Grand Jury.
Our response:
Because of the serious responsibilities of the Special Grand Jury in investigating alleged judicial violations, it makes common sense not to have the SGJ in close proximity to the judiciary to avoid any possible interference by such members. For instance, we don't want any Jurors sitting in a cafeteria or a local restaurant at a table next to the very judge whom they are investigating.
Just like any jury is to remain secluded and apart from the general population during their jury duties to avoid distraction or influence, the same caution must be given to the SGJ. It has nothing to do with "paranoia" --it is just pure common sense.