From where I'm sitting, the police officer DID "de-escalate" the situation. By using their weapon to shoot the violent criminal. At that point, the violence was "de-escalated".
Appropriate use of force IS de-escalation, as well as protection of self and others. That's what peace officers are supposed to do. The social problem we currently have going on is that some feel use of force is never justified, and that violent criminals should be permitted to continue their mayhem. I think we need to re-educate the public on what the role of peace officers is, and what appropriate use of force is for. Over and over we see the protests and riots for the criminals shot, and then months later, after the lives of officers are ruined, truth in the form of evidence comes out. And police are vindicated, in the over whelming majority of shooting incidents.
IMO, it's as ridiculous as politicians lecturing the public that we just have to "get used to" civilian deaths from terrorist attacks, because they don't intend to do anything to stop the madness, for fear of "offending" the terrorists.
The world is upside down right now. That *offends* a lot of people.