I am beginning to wonder whether this guy was a patriot fighting Putin..or a terrorist selling this stuff...this is not your average spy killing....makes me wonder how much of this stuff is around?
Good question! This thing probably has more twists and turns than a LeCarre thriller. It seems reasonably clear to me that Litvinenko was an enemy of Putin and the quantities of polonium needed to kill him are thousands of times greater than what you can buy in the legitimate scientific supply market. So, applying Occam's Razor it seems to me Putin likely caused this to happen.
But exactly what Litvenenko was mixed up in, how the FSB caused this to happen and how the two Russian buddies and the Italian guy fit in, I have no idea!