Re: OTOH this may be a good thing ...
"Every false positive requires man-hours of work to chase up"
What? how? surely you look at 2 pictures and, as a human, give a yes and a no . You could do 1000 in an hour.
Not having a picture match hoewever , because you deleted the database results in 1 picture of an unknown person and the question "who the F is that ?" I put it to you that that will take a lot more man hours to figure out than if 2 pictures are the same person