JB - what is a "natural nurse"? Given the person in the video introduced herself as that I am curious as to what it is as I cannot find that role referenced in any of the RCN literature.
Here are some alternative views on test efficiency etc.
https://www.kevinmd.com/blog/2020/03/the-accuracy-of-covid-19-tests.html significantly different numbers than your shouty woman
https://www.medicinenet.com/script/main/art.asp?articlekey=228250 expalins some of the issues with testing and why false negatives in particular occur
https://www.snopes.com/news/2020/04/16/how-accurate-are-coronavirus-tests/
https://www.livescience.com/covid19-coronavirus-tests-false-negatives.html
As the Snopes article say no test is 100% accurate for a wide variety of reasons, yet the biggest problem is not false positives, but false negatives, so we should take test results under caution but they are the best approach we have at the moment for identifying those who have the virus and need may need medical intervention