The solution is simple though: politicians simply ask experts how many people die if they do X versus Y, and make sure it is recorded (e.g. by journalists) so they can refer to it later.
Why would any politician/regulator/expert willingly opt-in to accountability?
The best strategy (however cynical) is to not be quantitatively explicit about expectations so that you can frame it as though you succeeded no matter what happens.
Even assuming this utilitarian viewpoint is the correct one, you're putting a lot of faith in the general population to trust the experts / journalists and to be un-emotional when examining the facts.
