We should be surprised that anyone is surprised
A great many spiritual leaders and consciousness researchers have pointed this out for millennia: Most people sleepwalk through life, to the delight of advertisers, cultists and spin doctors everywhere, but hold on a minute: The term 'zombie' has negative connotations which does a discredit to the automatic behaviors which keep us safe from (e.g.) traffic accidents on a more than daily basis. Your unconscious mind makes sure you don't eat bad food, leave parties when the atmosphere isn't right, and all kinds of other useful things.
The 'true' Haitian zombie phenomenon relies on a particular drug program. Drug A (which has been identified as the puffer fish toxin) causes death-like symptoms leading to burial and so on. Drug B (a cocktail of nightshade alkaloids, usually based on datura) brings the subject 'back to life', only with the conscious mind 'removed', so that he can be sold into slavery or whatever, but still be 'useful' - all the neural responses which might make someone an industrious sugar plantation worker, for example, can still be in place. (Just think how stupid bees are, next time you munch a honey sandwich).
I think it's a little sensationalist to use the term 'zombie' to mean simply 'unconscious', as the writer of this article has done. The unconscious mind is a fine and respectable thing, and deserves to be retrieved from the dark cobwebbed closet where Freud placed it a century or so ago. (Of course, without Freud, we might still have even uglier models of the mind).
Professor of Psychology at the University of California, Charles Tart's book 'Waking Up' is largely about how to escape your sleepwalker self. If you want the 'airy fairy' version, read some Gurdjieff or even Nietzsche. (The Übermensch is arguably one who overcomes zombie-like behavior).
Cybernetics pioneer Gregory Bateson once said that he was not at all surprised that we had an unconscious mind (the zombie part), but that he was very surprised that we had a conscious mind. It's clear that the conscious mind represents a tiny fraction of what who we are, but ironically it is the largest part of who we think we are.