J.B.,

While the focus of the NAS report was indeed on polygraph screening, the polygraph review panel did make conclusions with regard to polygraphy in general. These conclusions are enumerated at the beginning of Chapter 8 of the report, before the conclusions regarding polygraph screening in particular.

I do not wish to be argumentative, but I think it is important to emphasize that  the NAS's conclusion that "...[t]here is essentially no evidence on the incremental validity of polygraph testing, that is, its ability to add predictive value to that which can be achieved by other methods" was made with regard to polygraphy in general, and not just screening, as you (incorrectly) assumed. This fact may easily be checked by referring to the context in which the foregoing conclusion appeared.

The NAS concluded that there is essentially no evidence on the incremental validity of polygraph testing in general. This is a key conclusion that you cannot gainsay.