Give someone a geiger counter and they imagine they are health physicists.
Contrary to what this moron says, Santa Monica is Zone 2 for radon concentration. Average levels of 2-4 pCi/L, though individual dwellings can obviously differ from the average. He says that alphas are penetrating his detector, but the window is likely too thick for that (it's thin enough for about an 18% efficiency of 5.5 MeV alphas). He's mostly measuring betas, followed by gammas.
And he seems to have a granite countertop, which is likely emitting radon.
Stop imagining and try to start thinking.