Risk registers are used by government departments and more generally by private companies to plan for worst-case scenarios. They range on everything from flu epidemics to terrorist attacks. As you can imagine, publishing these documents could cause unnecessary alarm and compromise sensitive information and investigations.
If the Government publishes the NHS risk register, it would then set a precedent to publish all registers. An unintended but dangerous consequence would be that government officials hold back vital information for fear of being connected with bad news. The most significant risks would therefore no longer be recorded, and no contingency plans would be identified.
This is a common argument used by the government against transparency. It is formidably stupid. In what universe is it a good idea to specifically protect the practice of giving advice you are not willing to explain, defend, or take responsibility for? I mean, this is cracksmokingly insane. Let's work through the process.
So I'm a civil servant, and am responsible for working up policy options on some issue. I have a brilliant idea that will solve the problem at a stroke. But for some reason, it is so politically unpopular, embarrassing, or evil in an ethical sense that I would be afraid or ashamed to put my name to it. Further, even if it works, it is still so awful that neither me nor my Minister would want to be associated with it. Not just that, it's so clever that despite being conspicuously weird, violently anathema to some major section of public opinion, or monstrous, and capable of resolving a major issue of public concern, nobody will notice it when it happens.
This last is required, because if they did notice it, it would surely not take too long to head over to data.gov.uk and look up the Department's organisation chart.
How likely is this? How likely is it that politicians would refuse to take credit, deserved credit, for something successful?
On the other hand, how likely is it that policy advice whose author is unwilling to take responsibility for it is bad advice? If you give people an out like this, you're likely to get more ideas that are evil, politically impossible, or simply idiotic. These classes of ideas will always be out there, and one of the reasons why we have things like public records and select committees is to act as a restraining influence on their production. "What would the papers say?" is not a stupid or cowardly statement. The constraint that your ideas should be defensible is a useful discipline, and one that may even be an aid to creativity, like the rules of a sonnet.
As far as I know, this argument was originally aired during the Franks report inquest into the Falklands War. On that occasion, the policy recommendation was "well, sort of vaguely wave our hands, and hope the fascist dictator eats Benny quietly and nobody notices. Let the file mature a bit". I think it is obvious that this was not the civil service's finest hour, and the prospect of public scrutiny might have induced someone to come up with a better plan and perhaps be more honest about it.
A further problem is that what the quote is describing is essentially the Noble Lie so dear to Leo Strauss. This is what designers and computer scientists call an anti-pattern - a common example of indefensibly awful practice. It is not actually impossible that the situation above might arise. Perhaps we do need to introduce an alien DNA virus into the school milk to induce immunity against Case NIGHTMARE GREEN. However, it is far more likely that the civil servant involved is actually doing just what it looks like, proposing a horrifically dangerous, stupid, irresponsible, and evil plan that ought never to have been thought for more than seconds. In fact, fundamental cognitive biases mean that someone whose idea is stupid, evil, or impossible and they know it, or whose motives are corrupt, is very likely to make use of such an argument to protect themselves.
I think of this as a She Was Asking For It argument - it isn't impossible that she was, but it is infinitely more likely that you are just trying to wriggle out of the consequences of your own behaviour, and therefore it is a safe aim-off to treat all such arguments as being dishonest. Once you admit the possibility, you're going to get a lot of shit in the meat.
Beyond that, we can knock off the other arguments quickly. Civil servants might be afraid of punishment for airing ideas considered weird. Well that's why we have a professional civil service with independent line management. The problem isn't the idea, it's the practice of punishing people for thinking. The public might be alarmed. Bullshit! Blah blah politically embarrassing. Grow up. The register might contain secret information. Well that's what the complex disclosure machinery in the Freedom of Information Act is for. We already fixed it.
Advice of the form "If I were you, I'd do X. But don't tell anyone I told you, and I don't want to take any responsibility for this." is probably bad advice.