And, back into the gray area; do you consider Amb. Hodin from The Mark of Gideon the planet's leader? If so, David Hurst is still alive. And grayer yet; do you consider the Vian 'leader' from The Empath to be a planetary leader? If so, Alan Bergmann is also alive.
Actually Hodin (Hurst) is who I was thinking of.
I don't know if it was said that the Vian experiment leader was the leader of his world, but these are not hard and fast rules.