It's roughly consistent with the data from South Korea which was quite liberal with testing potential cases based on contact tracing (so they have records of al

It's roughly consistent with the data from South Korea which was quite liberal with testing potential cases based on contact tracing (so they have records of also the infected but asymptomatic or very mild symptomatic carriers) and they got 0.6%-0.7% case fatality rate, and the median time from infection to death is something like 3 weeks. You get a much higher fatality rate if you're testing only people with severe symptoms or those who get hospitalized, which is what many countries are doing. For example, if you have mild symptoms, UK health service will tell you to isolate at home and call them for hospitalizatin if you get worse, and you'll get tested only if that happens. You also get a much higher fatality rate if hospitals are overloaded and people can't get proper lifesaving treatment, which wasn't the case yet in USA, so an estimate based on these numbers seems reasonable now.