Yes, but don't you get it? AFTER the exodus from Africa, the two populations were living in the same region (europe), but did not inter-mix at all anymore. Otherwise there would be more DNA in the europeans.
Why mix when in the middle east and then refuse to mix when in Europe?
I do not think that human history occurred the way you think it occurred.
How did it happen then? It appears you have no idea
This is a good question and I have no idea why you're being downvoted. I think I've heard there's evidence that interbreeding happened in Europe as well.