It is not a surprise that Lady Butler-Sloss has stepped down as chair of the independent inquiry panel into child abuse: a critical mass of stories had built up against her which meant it was impossible for her to continue leading an inquiry that is partly about conspiracy theories without herself becoming the target of conspiracy theories which would eventually weaken her findings.
A resignation before the inquiry has even kicked off is a serious blow to the government, which had been trying so hard to play conspiracy whack-a-mole, to stay ahead of the critics by acting fast and appointing big names to lead big investigations into historic allegations. But it is not quite right to say that this is a blow to David Cameron's authority. Of course by extension everything that the government gets wrong is a blow to the Prime Minister. But more specifically this is a blow to the Home Office, who appointed Butler-Sloss in a hurry. They would have announced her appointment to the panel even quicker than they did if she'd responded by the time Theresa May stood up in the Commons to give her statement on the matter on Monday afternoon. There seems to have been a rush to make the appointment - perhaps a naivety, even - that meant the links journalists were able to dig up very quickly indeed were missed.
The next appointee is not expected to be announced today. It would be wise for the Home Office and Number 10 to take a little longer to consider whether someone who seems very impressive on the surface is going to stand up to the full scrutiny of the press and conspiracy theorists who are convinced that an inquiry about the Establishment has already fallen prey to an establishment stitch-up.