I couldn't find any detailed write up about their selection methods for participants, only the basics of where they found them. Without that, it is very hard to determine whether or not there's some flavor of selection bias: If it is voluntary, and they do not screen out people who report having had cold/flu symptoms, then they run the risk of attracting a disproportionate number of people who volunteer because they're curious if their prior symptoms were actually coronavirus. That would make it far from a random sample. The fact that they sampled only people actually leaving their house is also a form of selection bias: these are the people more likely to be exposed and may represent a disproportionately high infection rate as well.
So I await further information.
That said, even if it's overall 0.6%, that is still 6x higher than flu, and higher than H1N1 which had a CFR around 0.1 for areas with adequate health care. (much higher when there was not adequate care, but that is not dissimilar to Covid.)
So no matter what, no one should be walking away from this study saying "See it's no big deal! Just the Flu/Cold etc!"
You may be looking at "settled" numbers when all was said & done and all facts were known. That's not an "apples to apples" comparison with current covid-19 knowledge.
Here's my source [0] and the relevant quote, below. It is the CFR during the H1N1 pandemic, 10 weeks into it, which is why it is a much more appropriate (though not perfect) "apples to apples" comparison with Covid-19:
>"The overall case fatality rate as of 16 July 2009 (10 weeks after the first international alert) with pandemic H1N1 influenza varied from 0.1% to 5.1% depending on the country."
So I await further information.
That said, even if it's overall 0.6%, that is still 6x higher than flu, and higher than H1N1 which had a CFR around 0.1 for areas with adequate health care. (much higher when there was not adequate care, but that is not dissimilar to Covid.)
So no matter what, no one should be walking away from this study saying "See it's no big deal! Just the Flu/Cold etc!"