A verdict has been reached, and necessary IG enforcement actions have been taken. For anyone who desires to cite this case in the future, the final verdict was:
"The Magistrates find the defendant guilty of appointing a placeholder Duke with the intent of returning the position to its previous holder at the earliest opportunity. While technically the placeholder was offered a choice as to whether or not to step down from the Duchy command, the intent of the appointment was made clear from the first. As a result of this, the Ruler who made the appointments will be stripped of all titles for a minimum of two weeks. The Duke who was granted his position back will also be stripped of his titles for the same duration."
Magistrates voted 7-0 in favor of the guilty verdict, with 1 in favor of a warning and 6 in favor of stripping the titles of the Ruler and Duke. Titles have been stripped. This thread will be locked after a few more days.