I am not going to argue with you; I don't believe it, but I realize you just read about this.
If you take "all precautions" and everyone is wearing a mask at all times in rehearsal (and in close contact an N95), 62 masked people are not going to instantly get infected. Something is amiss in this story.
Re patients without masks, covid patients have to be examined and in some cases intubated etc. You cannot examine someone's nose and throat and lungs if they are wearing a mask. An EMT enters an apartment and a sick person is coughing without a mask. Healthcare workers protect themselves and don't get sick. This story makes no sense. Someone dropped the ball.