He didn't ask about whether neanderthals and lucy are direct ancestors. It's known in the scientific community that they are not, they're off-the-line from Homo Sapiens. We SHARE ancestors with them. None of this is a problem for evolution.
What he was asking is how do you explain the existence of Adam in the light of knowledge of the Neanderthal race, it being dated to 12,000+ years? (I am assuming he is also asking how this conflicts with the age-of-the-earth issues of creation, Adam's existence having been dated to about 6,000 years ago).