This is what your link states.
Writing with a keen appreciation for genuine science, Coulter reveals that the so-called "gaps" in the theory of evolution are all there is -- Darwinism is nothing but a gap. After 150 years of dedicated searching into the fossil record, evolution's proponents have failed utterly to substantiate its claims. And a long line of supposed evidence, from the infamous Piltdown Man to the "evolving" peppered moths of England, has been exposed as hoaxes. [sic]
The Piltdown Man was a hoax. It was a presented for a reason and used as evidence(and not as evidence against evolution) for a time.
How do you know it's a hoax? How would someone who doesn't accept evolution argue that Piltdown is a hoax?