Let me preemptively disclaim that I do have nitpicks about the talk I linked, but IMO his main argument is sound.
In particular I think his scientific explanations aren't always fully accurate, and he worries about measurement minutia very strenuously. Also at one point he says you could breathe 80% radon/20% oxygen, which while chemically this is true, radiologically it would be suicidal.
Those nitpicks aside, his point about the EPA LNT model having no clothes is spot on. After "the scales fell from my eyes," now I can't not notice how all those same Party Line Claims get parroted in every piece of radon-related content.
Another glimpse down the rabbit hole is this interview with the late Dr Bernie Cohen, who studied the link between residential radon and cancer:
https://youtu.be/xhkBLhw-8pk
