They still got infected because the distance in the room was insufficient. Droplets can travel farther and can remain in the air longer than we had thought; the choir members were singing, which is more dangerous than ordinary talking. (People in bars tend to shout, a factor in making bars such hot spots.)

In a store yesterday, I saw a woman and child wearing masks (somewhat fewer than half the people in my small town wear masks in public), but the masks were pulled down past their noses, which meant they were protecting others from droplets but exposing themselves.

A rational approach, promoted by a rational governor would be a welcome change.