I don't think he's trying to mislead people on that one, but there can be two interpretations of 'laminar' that I think were confused in this case.Several times he said hyper velocity laminar flow out of the slots. Laminar flow? I think he meant "turbulent" flow to prevent "separated".
Ugh, a bit like claims of "area rule".
Certainly with the double slats, he will have accelerated layers of air (laminar). But the entire depth of the boundary layer will NOT be laminar, certainly not beyond the slats.
If he had used the terms 'attached' and 'separated' rather than 'laminar' and 'turbulent' he would have been using industry-correct terminology.
But IMHO the ideas he was communicating are the same, despite the confused terminology.