In April, more than half of infections in Germany happened in nursing homes and hospitals. Also, iirc it was very unevenly spread across regions (also consider

In April, more than half of infections in Germany happened in nursing homes and hospitals. Also, iirc it was very unevenly spread across regions (also consider that often it was superspreader events that drove up the numbers, it was not a even distribution across the whole population). That makes me suspicious of the paper, as there may be many confounding variables, and small sample sizes. People may also have started using maskes or other measures before the government mandate, especially the professionals in nursing homes and hospitals.