Where's Waterbury gone? No biology,eh? Biochemistry is so much more complicated in practice than physical chemistry, for example so many variations of common enzymes.
I'm surprised he regards the scientists using sophisticated instruments whose principles are well understood by them as though they were consumers of domestic appliances.
There is absolutely nothing wrong to me in principle with hoiking up the sensitivity beyond the manufacturer's recommendations in the context of this test. I was performing PCR years ago long before there were machines for the job...makes me feel quite nostalgic...it entailed a certain amount of improvisation and what we fondly called our *bucket chemistry" trial and error honing (can you hone a fluid?) our buffers.
The scientist utilises the tool.
Dr.Waterbury is being disingenuous with us. He should know all about quality control methods and the largest margin of error (narrowest range guaranteed) sought by manufacturers and still be reasonable/competitive. There are at least 2 reasons for this:
1. liability
2. room for "improvement" for a subsequent model.
As for the inability to retest because the sample was destroyed, a scientist would still report the findings, not throw them out. We find the findings.

And we report them
...I just isolated a teeny tiny quantity of unknown genetic material from inside a meteorite, but the sample was consumed. The genie's out of the bottle, mate.
Usually one of the things you learn when you become as advanced in your studies as you have is not only an awareness of how much there is still to know of one's own metier, but a humble appreciation of how damn. little you probably know about anyone else's