The case is technically about special fissionable material (regulation of nuclear weapons)—not radiological hazards—but all your points stand. Absurd lack of common sense all around.
So if everyone in Australia ordered one of these, what would they need to do to make it into a bomb?
I mean, hell, a pack of cigarettes contains polonium and lead -210. And Australians smoke quite a bit, last I checked.
Well, the police also said he bought mercury, which "can be used in switches for a dirty bomb", which is such a stupid thing to say, because a mercury switch is just an old form of a tilt switch. The idea that someone would buy mercury for making his own tilt switch is just so wild, but of course, they just put this BS out there to scare people and justify their completely overblown reaction.