OK, my point is that you are assuming that "modern" non-urban subsistence tribes show the same social norms as pre-historic humans. This is reasonable, yet not definate. But let's go with it. Does it preclude meaningful interbreeding barring other factors? I'd say no. Taking the women of other tribes and forcing them into your tribe, is a behavior of many "primitives". Thus Neanderthal women would have been expected to rear their ugly heads (so to speak) in the gene pool, which DNA study claims to preclude. That's why I'm guessing there were stronger factors involved.
We do not find mixed communities. That means, we do not find communities of Neanderthal women 'taken' into human tribes. Now, if you want to just conjecture that Neanderthal women were abducted and taken into human tribes as some kind of work horse sex slaves, even though we find no archaeological evidence of that, then that's fine by me, but don't criticize me for making assumptions!