If I’m correct that Dax is actually making a cogent point here, I think it’s that you can only really use the (classic) nasal test as a measure of the Abbott test if the former is nearly 100% accurate. If the nasal test is prone to false positives then it’s tough to argue it is proving the Abbott test is prone to false negatives.
Don’t know if any of that is true, just fleshing it out.