This is dangerous in so many ways. Let's assume the virus actually is deadly for the sake of argument. False positives will allocate much needed resources to people who don't need it, including contract tracing on someone who never had it. False positives could swing the mortality in either direction. If they test everyone in the hospital, someone dying of plain old renal failure or cancer with a false positive would increase the mortality rate. On the other end, routine testing of healthy people would decrease the "mortality rate" since they obviously can't die from a false positive.

Basically, garbage data leads to garbage conclusions.