Let me preface this by saying I am in no way trying to "Monday morning quarterback" this incident. This doctor's decisive actions saved dozens of lives.

To facilitate discussion though, I'd like to highlight this section:

"By textbook standards, some of these first arrivals should have been black tags, but I sent them to the red tag area anyway. I didn’t black tag a single one. We took everybody that came in—I pulled at least 10 people from cars that I knew were dead—and sent them straight back to Station 1 so that another doc could see them."

There is a reason the "textbook" calls for a black tag. The simplest definition of a "mass casualty incident" is when you need more resources than you have. Sending those dead patients to the treatment area was a waste of the most critical resource they had (the time and attention of medical providers). It is likely some outcomes were worsened by that waste of resources.