You do not understand. He was fleeing for his life. He did not want to let Western doctors (or drop in visitors) to "establish" anything, he did not trust them.
As a victim his value would be much greater for anti-Russian propaganda than Litvinienko (the first was Russian prime minister and the second was a small time charlatan) and he knew it.
Capt. McCluskey: "I thought I got all you Guinea hoods locked up! What the hell are you doing here?"
Any clue who "Russia's political enemies" would be in this case?