If you’re an editor about to send a famous and sympathetic writer to interview one of the world’s most notorious villains, here’s how you might prep him:

First, drill him on his assumptions and make sure there is an intellectual argument elsewhere to back him up.

Then, you’d likely remind him that his loyalty should be with his readers, not his subject. And you’d reinforce that by helping him anticipate the natural questions those readers might bring to such a controversial interview.

You’d want to see his interview questions ahead of time to ensure they are asked in neutral language that will hold your notorious source accountable.

Of course you’d advise him that it’s unacceptable to cut a deal that provides the source with prior review.

And finally, you’d remind him that the story must be well-reported and intellectually honest, so that it could stand on its own without a byline. That’s how you know it’s worth the paper it’s printed on.

It’s common for a writer’s ambitions to outpace his talents. (Sean Penn, you are no Hunter S. Thompson). That’s what editors are for. The best editors lift writers above the level they might reach on their own. They bring discipline to wandering pieces. They force writers to nail down assumptions and abandon unnecessary prose.

The editor’s role on the front end is the easy work. All he had to do was prepare Penn to set aside his own ego and go into the interview with his loyalties firmly on the side of Rolling Stone’s audience. But that front end work often makes the heavy lifting on the back side a bit lighter. During the actual writing, an editor should have been working with Penn to identify a structure, build a coherent argument and then challenge readers to see a complicated character operating in a complicated system.

How do you do that? You have to bring in other voices. Here’s what’s missing from Penn’s El Chapo piece:

  • A sociologist or economist. If you want to argue that American capitalism and social structures are partially culpable for the mob state that created El Chapo’s kingdom, bring in an economic expert who’s done research in this area.
  • A law enforcement specialist. There are plenty of people who argue that America’s criminalization of drugs harms Mexico. But you can’t just toss that out as an accepted fact. Your readers deserve to hear about the successful experiments in decriminalization.
  • Regional economic data. Rather than letting your source proclaim that there are no options, bring in some basic economic data that provide context.
  • His neighbors. Penn claims El Chapo is a "Robin Hood-like figure" who improves life for the poor people of his hometown in his home state of Sinaloa. Let’s hear from them.
  • A victim’s family. This may be the biggest stakeholder missing from the story.
  • A Mexican newspaper editor, like this one. Cartels have terrorized journalists. Their voices would add some needed accountability.

Rolling Stone founder Jann Wenner seems to have been in the best position to influence the story, communicating with Penn before his interview and working with the author on his first draft, according to a New York Times article. Managing Editor Jason Fine came in around the time the lawyer was brought in, the Times article states. That may be where Rolling Stone went astray.

In one of his more indulgent graphs, Penn describes looking at his penis while taking a piss and wondering if he might lose it as retribution for a misstep. In retrospect, Fine was really the person who should have been worried about losing his manhood, being brought in at the last minute to line edit a piece that had been crafted by his publisher and a notoriously impetuous actor.

The big lesson from Rolling Stone’s last debacle, "A Rape on Campus," was that legendary magazine’s editing process had failed. It’s a lesson the institution is still struggling to learn.