David Habbakuk will be familiar to readers of Col Pat Lang's blog Sic Semper Tyrannis. He has some very interesting thoughts on the November 2006 death of Alexander Litvinenko over at Yuri Mamchur's Russia Blog:
Uncritical acceptance of claims by [Oleg] Gordievsky about how Litvinenko died is particular bizarre -- given that he has made different and incompatible claims at different times, so as a simple point of logic some of what he has claimed has to be false. A further curious feature of Gordievsky's accounts, however, is that much of what he has claimed directly contradicts central elements of what has become the official British version of Litvinenko's death. And in fact, while one would be ill-advised to take anything Gordievsky says at face value, some of what he has claimed fits in distinctly better with the publicly available evidence than the official version does.