Science as a field does not accept frauds, including those that support the mainstream, well-accepted theories.
Yes, in an ideal world, science would be based solely on facts.

But it's a human endeavour, mistakes are made, in most fields of science.
Especially when you have an axe to grind or an assumption to prove.
It's a little hard though, to be sure certain parts found actually belong to the same organism, when the individual bones were scattered and incomplete (fragmentation).
So in case of Lucy, the actual fossils are not the hoax, although there are doubts the bones are from the same organism, but the artist's rendition, with human feet, is nothing more than an educated guess.
This is how it is a hoax, because it (Lucy as a reconstructed hominid) is presented as factual and scientific, purported to be a missing link between man and ape,within the paradigm of an ambiguous 19th century conjecture (Darwinism), but it is just a suggestion, an interpretation of the collection of strewn bones gathered.
Australopithecines are a group of extinct apes closely related to modern chimpanzees and orangutans.
Further studies of Lucy seem to indicate she was probably a 'knuckle-dragger'
The reconstructed pelvis does look compelling though, i must admit that.
But, since there is no evidence to support DNA codes itself to obtain positive development needed to get form Lucy to man, or from any 'hominid' to man, we can conclude Australopithecines simply went extinct.
However, i can see why people are convinced by such fossil interpretations.
Also because it is backed up by the large opinionmakers of the world.
I will stop calling Lucy a hoax though, because jumping to conclusions and making assumptions is not what a hoax is.
some reference:
http://www.jpost.com/Health-and-Sci...archers-Lucy-is-not-direct-ancestor-of-humans