That’s an issue we’ve highlighted from early on and I don’t think there are any answers. The more asymptomatic cases there are, the lower the morbidity percentage and possibly the more immunity there is. It would be interesting to see if that asymptomatic positive person tested positive for antibodies as well.
Also, I have read from the experience in China that some people keep testing positive regardless. Odd I know. I read about one poor guy in China who is still personally locked down, despite appearing perfectly healthy, because he keeps testing positive. There must be an explanation somewhere for why that can happen, but I have not read anything on the possible reasons.