The Uvalde School Police Chief then took 'command' of the scene and was ordering all the other city police, county sheriffs, and SWAT teams that showed up to stand down.
Meanwhile, teachers inside the school were still calling 911 begging for help.
He was well known as an incompetent. In situations like that, you ignore a clown and deal with it later. That is exactly what the Border Patrol men did.
That. The worst law enforcement failure was leadership. The Incident Commander ordered that nothing be done, and LEOs stood around, following orders. If his order had been "follow me" or "Jim, you are in tactical command. Breach the door, and end this NOW!" I think that almost all, perhaps all, of the officers condemned as cowards would have followed.