The Red Arrows are thought routinely to take ground crew in rear seats to airshows when they plan to be based away from Scampton. Back seat rides are also a much sought after perk.
It is distressing that life was lost in this accident, but that should not stop the practice. When the facts emerge, they may well reveal that the irretrievable emergency occurred when the aircraft was very near the ground. Certainly the passenger would have been fully briefed.