His reply is a bit vague, but as I recall this has actually been studied and it turns out that (for instance) other animals have blood coagulation systems that are lacking several of the 30 supposedly essential parts and still work fine - see e.g. http://creationwiki.org/Blood_clotting_is_irreducibly_comple... and the usual anti-creationism resources. Similarly, the supposedly "irreducably complex" bacterial motors turn out to be made of components that originally evolved for other purposes and were repurposed.