That doesn't come out of a reading of the Wikipedia article. So where does it come from?
You seem to be putting great store on a person saying they have no actual existence.
How can we know that? There is nothing as yet that links Cotard's with P zombie state in your citation from wikipedia. Surely sleep is closer to P Zombie. Cotard's sounds too complicated to act as any sort of model for P Zombieism. It is more like an altered state of consciousness rather than uonconsciousness.
You seem to be merely accepting the testimony of the subjective whenever you see it fits your argument, ergo, mere polish.
"During psychopathological
examination, we saw an agitated,
suspicious patient with severely
affected formal thinking. He
reported being dead since he had
drowned in a lake years before, and
said that he had been reanimated as
a zombie by radiation from mobile
telephones. He was under the
impression that he was still under
water, and that everybody else had
also drowned and become
a zombie. The patient explained
that although it was morally wrong
to exert violence on living persons,
there was nothing wrong with
beating up zombies. He wasn’t
afraid of retaliation or legal
prosecution, because he believed
himself to be dead and to have no
feelings."
http://tinyurl.com/Cotzombie