Maybe I just need a little more coffee, but I'm still wondering about this mtDNA conclusion.
Let's say we have ten generations of females, mother-daughter-daughter...
The first mother in the sequence is pure-CM. She mates with a pure Neandertal and so does every female down the line. (I know, just a thought experiment.)
The tenth lady has mtDNA telling us she's CM. She looks like a Neandertal, as she jolly well ought after all those Neandertal male ancestors.
My question is, are we looking at anything besides her mtDNA? And is mtDNA by itself, in a case like hers, telling us what we need to know? In other words is it giving us truth or just fact?
The honest answer is that I don't know right off-top how to answer your question about the mtDNA.