Obviously, the Hadar knee joint (found before Lucy BTW) could not be part of Lucy. However, this claim has never been made, despite the lies of creationists.
The problem seem to have arisen after a lecture by Johanson at the University of Missouri on November 20, 1986. In the Q&A session afterwards, the following was recorded:
Q. How far away from Lucy did you find the knee? A. Sixty to seventy meters lower in the strata and two to three kilometers away.
From context, Johanson was referring to the separate Hadar find, but creationists make the claim that he was referring to Lucy's knee (which is actually incomplete on both legs). The situation is made more complex by the habit of some creationists of using the name Lucy instead of Australopithecus to refer to the whole line. Lucy is one specimin of Australopithecus.
From the "essay" after he has made a "few rewordings to make it more proper" -- it still says: "Someone who cares" with no basis on facts writes:
Lucy’s inner ear structure, skull structure, and other bones show that she was most likely related to the pygmy chimpanzee. She did not even walk like humans do. When a knee joint for one find of Lucy was requested, they found one more than about 200 feet lower in the earth and about two miles away from the rest of her! How could that joint have possibly belonged to that particular Lucy find?
It has been pointed out to "Someone who cares" that this is not the truth and that the knee joint was not combined into the Lucy skeleton as part of that find.