That was my point. If you make checks than you might look at a single slide or so, or if a film identity gets lost, you shall view the film for an exposed identitycard, or for typical scenes to be checked against missing film requests.
But on a normal run even checking for long-wire scratches or so, you would look at the filmstrip as such and not at frames, and even then inserting virgin blank film and examining that would be more informative.
That is why I am puzzled by that statement from that Kodak-lab employee. THe same who had it about up to 10,000 cine-films per day.