Wow, 85 times higher then thought.
The good thing about this study is that they picked a really typical American county -- Santa Clara County, better known as Silicon Valley, and, according to Wiki, the place with "the third highest GDP in the world, after Zurich, Switzerland and Oslo, Norway" and "the most affluent county on the West Coast of the United States..." with an income of "$94587 per capita, roughly on a par with Qatar..."
The average age there is...37.
It was also one of the earliest places to enforce social distancing and lockdown, and has some of the best medical facilities in the world, including free clinics. Think any of that might have had an impact on the number of deaths? Remember, there are two components to this study -- the number of infected and the number of deaths. Changing either one of them impacts the mortality rate. I would suggest that the mortality rate there is unusually low.
Unlike what Joe suggests, it's not "85 times" the number of confirmed cases -- the study suggests the number may be 50 to 85 times the number. He cherry-picked the high number. And just out of curiosity, I'd like to know why that range is so large. In fact, it doesn't sound like a random study to me. It sounds like something else, but anything else probably would have been shot down by now. A typical range for a good random study with a 95 percent confidence level (the standard for most social research) would be closer to 6%, not 40%.