Your argument is based on a false presumption: That "ape" is a species designation. It is not.
It is a name for a larger grouping of diverse animals, like the name "bird". Just as not all birds can interbreed, not all apes can interbreed. And yet, this doesn't mean that a penguin is not a bird just because it can't impregnate a swan, nor does this mean that humans aren't apes just because they can't impregnate orangutans.
Your link made that association. They explained the evolution of man as the interbreeding of dogs. Not knowing the difference and thank you for point it out to me I was under the assumption that it was a true statement.