Last time a Russian double agent died from a poisoning in the UK, the person the victim named as his murderer on his deathbed was elected to the Russian State Duma. Stop taking us for idiots.
Yeah, the Russian intelligence agent known to met the suspect shortly before the poisoning and been present at other areas where polonium was found, known to have rushed back to Russia to have a medical test, and then been named by the suspect as the man handing out the fateful teacup is definitely an unlikely candidate to have carried out the poisoning, and the reason he's since sat in the State Duma and hosted a TV show called "Traitors" is because the Russian state apparatus is completely convinced he was actually a friend and ally of defector Litvinenko and not the man who bumped him off.
Nobody is stupid enough to honestly believe that. Nobody. Jog on troll.