As noted - the MO fits KGB practice of publicly poisoning KGB defectors. There is no way Polonium could have accidentally got into ONLY Litvinenko's food, irrc he was at a Sushi restaurant, so it's even less likely.
His death was painful and agonising - even if Polonium had not been detected his high profile and his sudden deterioration in health after his accusing Putin of murder would fuel conspiracy theories. Further, the use of Polonium indicates access to a nuclear reactor, which points to the Russian State.
Application of Ockham's Razor suggests the murder was ordered by Putin or someone close to him. Given Putin's control of the Oligarchs, it hardly matter which. One of the suspected assassins subsequently became a member of the Durma.
This is just what I remember from the news reports at the time.
Bookmarks