- The data is from one county in CA ...
- ... for the time period June 3 - June 25, about 3 weeks
- Neighboring counties did not have mask mandates at the time, meaning that anyone traveling between counties and not wearing their mask would have spread COVID-19 to Alameda County just as well as if no mask mandate existed
- The article notes that the most likely explanation for the lack of a different outcome from neighboring counties is that people either do not follow mask mandates or do not wear effective masks
Pretty much a non-sequitor article AFAICT