That's not entirely true. A Joint Voluntary Dismissal could have been filed after a ruling, not matter which way he ruled. He was ruling on HG's counter suit,not the original case.
FYI "with prejudice" means that the plaintiff can never refile this lawsuit. This is significant because if a plaintiff was to just a drop a complaint they would do it without prejudice. When they motion for dismissal with prejudice it most always means they have come to a settlement agreement which requires them to dismiss with prejudice.