Rick Bowmer, Associated Press
In this Friday, Sept. 1, 2017, photo, nurse Alex Wubbels displays video frame grabs from SaltLake City Police Department body cams of herself being taken into custody, during an interview, in Salt Lake City. Officials at University of Utah Hospital where Wubbels was arrested after refusing to allow police to draw a patient's blood are apologizing that security officers didn't intervene and saying they've implemented policy changes.

SALT LAKE CITY — If the arrest of University Hospital nurse Alex Wubbels hadn’t been recorded by a video camera, would we know about it?

Would the police chief, the mayor and the chief of the university’s Department of Public Safety have publicly apologized and vowed to make changes? Would the district attorney have launched a criminal investigation? Would the detective involved and his watch commander have been put on leave?

In other words, would this big tree, felled in the midst of a forest of law enforcement and medical professionals, have made any noise?

The answer to virtually of those questions appears to be no.

A nurse was arrested because she followed her supervisor’s direction not to obey police orders to draw blood from a patient who was not conscious, not under arrest and not the subject of a warrant. The arresting officer and his supervisor said she was wrong. He said, she said; the officer lost his cool, the nurse was released a while later. Some dry police reports result. Few people care.

Until they see it.

A century and a half ago, photographer Matthew Brady proved that no retelling of a traumatic event could substitute for actually seeing it. When he showed dead soldiers in photos of the Antietam battlefield, the New York Times said, “If he has not brought bodies and laid them in our door-yards and along the streets, he has done something very like it …”

And now nurse Wubbels has reminded us that 19 minutes and 22 seconds of living color can put police departments and a City Hall on their heels faster than any written complaint or police report could hope to do.

All is not amiss in the brave new world where social media continually boils in our periphery like a cauldron of nastiness and discontent. Sometimes the brew takes on a righteous indignation that spurs justice.

At a press conference last week, Salt Lake Police Chief Mike Brown said that within 24 hours of Wubbels' arrest on July 26, police officials had met with those involved and begun a review.

But Brown didn’t see the video until last week, a month after it happened. Neither did Mayor Jackie Biskupski. That’s when they began using words such as “completely unacceptable,” and, “I was alarmed by what I saw.” It’s when the mayor apologized personally to Wubbles and, in her words, instructed Brown to do a thorough review.

The university’s chief of public safety, Dale Brophy, wasn’t passionate about the incident either, until he saw it. Then came the apology and a statement that no longer required the usual “let’s wait for the facts” sort of hedging.

“It was clear that the arrest was completely mishandled, was inappropriate and didn’t need to happen,” the Deseret News quoted him as saying.

Finally, Salt Lake County District Attorney Sim Gill saw the video and called for a criminal investigation. The Utah Legislature passed a law in 2016 making an assault on a medical professional a felony.

Once Gill made that statement, detective Payne and presumably the watch commander, Lt. James Tracy (this has been widely reported but not confirmed or denied by police) were suspended with pay.

In true Matthew Brady fashion, Wubbles figuratively laid the bodies of her arrest in our door-yards and along the streets, and that made all the difference.

Brady never had to deal with that nasty cauldron of social media. If he had, the tweets and Facebook posts surrounding the 22,717 dead, wounded and missing at Antietam might have brought pressure to change the outcome of the war, and perhaps not in a good way.

But Wubbles' case didn’t have those faceted edges, and the ensuing national outrage was perhaps more important than the video itself.

Police body cameras have been subject to debate nationwide. Chief among the objections is the argument that they show things out of context.

That can’t be said about the 19 minute, 22 second video. It demonstrates lawmakers’ wisdom in making police camera videos public record. It lives up to the promises of accountability that transparency can offer.

All you have to do is imagine how different things might have been without it.