The ONLY rational answer is that there should be a confidence level based on global expert opinion and what’s allowed should be a function of that confidence and the potential damage of being wrong. In the case of something like COVID, that’s synthesizing opinions based on the WHO as well as the public health departments of most major nations. In areas where they don’t clearly agree, you have to have to give more leeway than in areas where they do.

No, it’s not perfect but no perfect system exists and unfettered misinformation is demonstrably worse than relying on expert opinion. What you need to watch out for is corruption but that’s literally always a risk in any system. And if you’re going to claim corruption, then you’d better be willing to go to court with specific actionable evidence.