CV and mad panic behaviour

[LP]

I know someone who did a rapid test and a PCR within an hour of each other and the rapid was  negative but the PCR came back positive.

That's quite possible, PCR is almost 1000x more sensitive and will pick up an infection much earlier.

I've heard testing specialists advise that lateral flow tests(RAT) should be repeated about 3 days apart before an all clear is given. I think some states have something similar as a basic requirement. A lot of tests that can be bought come in pairs for that very reason.