When is an ape not an ape (according to Answers in Genesis)?

Creationists agree there is a distinct line between humans and apes. Most - though not all - think that the Australopithecines and possibly Homo Habilis were just apes, while everything from Homo Erectus onwards was fully human.

Interestingly however, Answersingenesis have published a paper claiming one of the more recent hominins discovered, Australopithecus Sediba, was actually a human:

Results indicate that hominins may be divided into as many as four different holobaramins: (1) the genus Homo (including Australopithecus sediba), (2) the genus Paranthropus, (3) Australopithecus africanus, and (4) Gorilla, Pan, Australopithecus afarensis, and Australopithecus garhi. These results tentatively confirm the common creationist claim that fossil hominids can be divided into human and non-human categories. In contrast to many creationist claims, however, the present results indicate that Homo habilis, Homo rudolfensis, and—most surprisingly—Australopithecus sediba belong in the human holobaramin.

- Baraminological Analysis (AiG)

This however is the same site which has written several articles claiming "Lucy" and her species (Australopithecus Afarensis) were just apes:

Neither Lucy nor any other australopithecine is therefore intermediate between humans and African apes. Nor are they similar enough to humans to be any sort of ancestor of ours. Lucy and the australopithecines show nothing about human evolution, and should not be promoted as having any sort of “missing link” status. The creationist alternative, that humans, apes and other creatures were created that way in the beginning, remains the only explanation consistent with all the evidence.

- "Lucy" isn't the "missing link" (AiG)

So to ask the obvious question: How can one species of Australopithecus be considered human and another species be considered just an ape?

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