I got it wrong, it was actually the psychiatrist played by Ben Kingsley who said the line. It's earlier in the movie where he's discussing the various treatments done on the island and he brings up lobotomies. He says "Some say the patients become reasonable, docile. Others say they become zombies."

So saying the phrase like that would be a little anachronistic, since the conception of a zombie in 1954 would have been a magically bound slave. But I do kinda like the MKULTRA angle too.