The priest had been diagnosed with pneumonia. Instead of isolating by himself, he went back to live with his fellow Redeptorist brothers (seven, I think). They too chose not to isolate. Now five of them are positive for COVID. Two of them even said Mass at the Church in this article. There were two bad decisions made, or at least on really bad decision made. No one who is symptomatic, or lives with someone who is, should be out in public until testing can be done.
Time will tell if there is any statistically significant increase from those who attended Mass here, and that was the only contact with these priests. If not, then we know that we can continue with the Mass everywhere, with the same precautions. If there is an outbreak, and the cause can be traced to Mass, we might have to close everything again.
What bothers me most is not the safety guidelines being insufficient, but how resistant Americans are to following them. Our state has mostly re-opened with some great guidelines. Yet now it seems that most are not following them. Now bars are set to open. Human behavior being what it is will likely result in new cases of COVID continuing in the near future.