Nick Selby is one of the cops who takes his life into his own hands by questioning the herd. Even though he may not always ask the same questions you or I might ask, we don’t have to worry about our backup pulling a Serpico when our life is on the line. Nick does, but he asks the questions anyway. For this, he deserves respect.

For me, though, the pride was over more than just those acts of bravery; it was over the commitment to professionalism, trust and respect by the Dallas police that will allow the department to be as levelheaded in the aftermath of the massacre as it was in the midst of it.

Friday morning, after our brothers were assassinated for being white and for being officers, the word was sent out: more protests are expected, and we must not interfere with them. And that is the way it should be.

This may not seem so bold to outsiders, but there are a lot of cops who will view the murders in Dallas differently, who will see Selby’s call for calm in the “aftermath of the massacre” as heresy. They are not as concerned about the right to protest as they are about the assassination of their “brothers.”

And as day follows night, there was a protest march in Baton Rouge, Louisiana, where Alton Sterling was killed by two police officers.  In a court of law, the killing will likely pass muster under the reasonably scared cop rule. The law gives cops every benefit of the doubt. The court of public opinion is not always so kind to the police. Nor should it be, even though some can step back and see that there is enough loss in the past few days to justify giving everyone some breathing room.

But the protest went forward in Baton Rouge, and whether it was a good time to march or not, they did. That’s their right, and it’s not subject to outside approval.  Among the protesters was Deray Mckesson, one of the foremost voices of the Black Lives Matters movement, which desperately needs thoughtful voices.  He periscoped the protest. You won’t see any violence. You won’t see protesters carrying guns, throwing bottles, doing damage. You see people protesting, chanting, expressing their grievance about the killing of Alton Sterling and others.

And then Deray was arrested.

The New York Times covered the story.

The arrest occurred about 11:15 p.m. as Mr. Mckesson and other protesters were marching in Baton Rouge on Airline Highway, where they were warned by the police not to stray onto the road.

Mr. Mckesson, 31, repeatedly tells viewers that there is no sidewalk. Then, about five minutes into the broadcast, the video gets shaky and you hear the police say: “City police. You’re under arrest. Don’t fight me. Don’t fight me.” Then Mr. Mckesson shouts, “I’m under arrest, y’all.”

Within these words is a hidden bomb that will elude many. While people will recognize that there is a right to protest against the government, they will similarly accept the premise that protests against the government should follow the government’s rules, like not to “stray onto the road.” That’s not such a simple premise as would appear from the Times story.

State Police officials defended the arrests of Mr. Mckesson and others as a matter of public safety.

“Well, they’re clearly blocking the roadway,” a Louisiana State Political told Maya Lau, a reporter with The Advocate, in a video she posted on her Twitter account. “We welcome the protests. We want them to voice their opinions. That’s what we’re here to do, to make sure they’re safe and they’re able to do that.”

Arrested for their own safety makes for a very benign, almost generous, rationale. It sounds much better than “we arrested them because they pissed us off, and after what happened in Dallas, we weren’t in the mood to be pissed off.” Or worse.

Some of the protesters “strayed” over the white line in the road. Protest inside the lines. This detail will be seized upon by those who support the arrests and the police. It’s not a compelling justification for anyone not inclined to approve of the arrests otherwise. The video shows neither a serious impairment to others caused by the protest, or even a serious safety issue raised. As protests go, this one was about as orderly as it gets.

There was a judgment call to be made by the Baton Rouge police. Was this the opportune moment to inflame an already incendiary situation over what could at worst be characterized as a trivial violation?  While Deray is no more immune from arrest than anyone else, he will be a person, a name, a face, around which the anger of the Black Lives Matter movement can, and will, galvanize. Was this what the Baton Rouge police were trying to accomplish?

The police will mourn their dead in Dallas, as they should. There will be cops from across the country, in formal uniform, paying tribute to their brothers. And there will be protesters mourning their dead. They wear no uniform. They have no formal ritual. But they mourn as well.

The difference is that the police can arrest protesters, like Deray Mckesson, for not doing so in the manner they prescribe, whereas the protesters can’t arrest police. The police come at their decision with shields, guns, and the benefit of a system that not only accommodates their decision, but gives them the benefit of the doubt even if their decision is foolish.  The protesters have only their moral suasion.

The events of the past few days will be dissected, with people backing up in their usual corners to fight for their team.  There will be the usual spin, irrelevant details, preaching to the choir, red herrings and occasional sound point.  Nick Selby called for the police not to pour fuel on the fire. Instead, they arrested Deray.

It’s not that there aren’t cooler heads, but that they didn’t prevail in Baton Rouge, and things will only get worse as a result. The message sent was that the police have the power to stop the protest, to show protesters that no matter how outraged they are, the police are more powerful than they can ever be. This is the wrong message.