if your goal is to truly good-faith ask questions without getting the response you cite, it's entirely possible. The secret is to play dumb and make the person you're asking explicitly support each and every statement they are making in a way that would convince a normal person. Just keep asking reasonable questions and playing dumb. Then, at the very end, say slowly: "huh. well, ok, I guess you've explained your perspective, but there are these things that don't quite follow, and seem like they are just guesses or suppositions:" and list all the remaining problems. This is also an effective denial of service attack on the scientific infrastructure.

I don't think public health officials really want to be in the position of explaining their lack of certainty (combined with a set of previously established good practices that are likely to lead to good outcomes) about nearly anything, since we have a long history of noncompliance in patients and lack of certainly just leads to additional noncompliance.

I don't want to sound completely unsympathetic, as I've lived through multiple paradigm changes and I know well that scientists get defensive when you challenge their territory. but remember, we have to deal with the jenny mccarthy effect.