It may be that the their viral load was low or it may have just been a poor specimen. I have collected many Covid swabs. There is plenty of opportunity to get a sub-optimal specimen by the collector. If their symptoms were mild, it was irrelevant anyways because we sent them home and told them to quarantine until the results came back. I called hundreds of these people to tell them their results one way or the other. I talked to them at length and genuinely gave a **** about their wellbeing and 90% of them were feeling moderately to greatly improved by the time the results came back (2-3 days after their ER visit). A small percentage were feeling worse and I suggested they return to the ER and they did and they were admitted for Covid and they survived it and went home. One lady felt considerably worse but her Covid test was negative. I saw the doctor didn't bother to get a flu swab so I encouraged her to return for a flu swab and for further evaluation. I assume she did. I never saw.
Testing became more accurate as the pandemic rolled on and later on in the wave 2, our swab kits tested for Flu A and Flu B and RSV and Covid all at the same time.
I guess my point to all of this is that, as I have stated countless times, the case count is not terribly useful, it's the death count that provides us a true picture of the pandemic because that can not be BSed and I have already provided you multiple links to sources that confirm that the death count was actually underreported, not overreported as is typically proclaimed by the Covid non-believer types.
The case count was very useful to the political and media elites. They brainwashed a lot of people by constantly and loudly beating that drum.