You really aren't seeing this right. The MOS would have been able to stand this story up based on interviews with the staff. But the plain fact is that the staff aren't going to go on the record about it, so the royals have an easy win by simply denying that it was them. The simple fact is that the buck stops with them; whatever is done by the royal household (which may well include decisions to which they aren't party) is performed on their behalf.

A CEO can't simply say "my CFO did that" and get away with it. The royal household are working for the royal family, and any decision that they take is part of their duties to the royals. Why the royals get such a pass here is beyond me, but it's like North Korea; people believe in inherited genius.