This can happen, especially with diaspora Blacks and ESPECIALLY with ADOS.
Why?
Because even a "dark skinned" ADOS can have significant European blood. Don Cheadle is 20% European. Dave Chappelle is at least 25% European because of his white grandfather. Emmitt Smith is 12% European and 7% either Asian or Native American.
So you take a white American that's probably 96% to 100% Euro and mix them with a Black American that's 80% African? You get some random blends. The mixed people that "look" mostly Black (Obama, Lenny Kravitz etc) tend to have Black parents that likely aren't mixed with much.
The lady in the video is darker skinned but she could EASILY be 20 to 30% European and not even know it. The white doesn't show up ON HER but it showed up on the baby.