Originally Posted by
rda
With the case of Litvinenko's polonium things are much simpler and you are debating something that is irrelevant as if it was super-important. Yes, there was no tracing to the reactor (and maybe you are even right that such tracing would have been impossible to do under the circumstances or even in general, although I think that with a lot of material it should have been possible one way or another), but nobody was producing polonium in requisite amounts except a single Russian plant. That single Russian plant was producing the vast majority of it, was the only plant that was known to do it regularly and was the main source of polonium for everyone interested. That's it.
I *agree* that this is not enough to say 100% that polonium was from there, but it was enough to say it with 95% certainty and that's where things ended. Now, if you are going to argue that 95% is not 100%, then sure, it isn't, but it is 95% with polonium, 95% with this, 99% with that, 99.999% with some other thing, maybe 95% here with Novichok, so if you want to keep saying that nothing short of 100% would do, be my guest but nobody is going to buy it and they would be right not to buy it. It is too easy to make something not 100%, nothing is ever 100% in practice.