Last week, former Justice John Paul Stevens penned an op-ed for the Washington Post on “The Five Words that Can Fix the Second Amendment.” The piece is actually an excerpt from his new book Six Amendments: How and Why We Should Change the Constitution. In the book, Stevens suggests some changes that would ratify his view of cases in which he stridently dissented, such as Citizens United and Heller.

Stevens’s dissent in Heller, the case in which a 5–4 Court held that the Second Amendment conveys an individual right to own guns even for those not part of a militia, is largely re-hashed in his Washington Post op-ed. In addition, there is, or was, a glaring error that the Post has since corrected sub rosa, that is, without acknowledging at the bottom that the piece was edited. As Josh Blackman originally reported, and thankfully preserved by excerpting, the first version contained this error:

Following the massacre of grammar-school children in Newtown, Conn., in December 2012, high-powered automatic weapons have been used to kill innocent victims in more senseless public incidents.

As Josh and others noted, not only were automatic weapons not used at any recent high-profile mass shooting, they’ve been essentially illegal in the U.S. since 1934 and since 1986 they’ve been almost impossible to come by. Justice Stevens also repeated his error a few paragraphs down:

Thus, even as generously construed in Heller, the Second Amendment provides no obstacle to regulations prohibiting the ownership or use of the sorts of automatic weapons used in the tragic multiple killings in Virginia, Colorado and Arizona in recent years.

When you view the piece now, however, the words have magically disappeared. But they have not, apparently, disappeared from Justice Stevens’s book, which went to press with those errors. I don’t have a copy, but I checked by searching the inside of the book on Amazon for the word “automatic.”

Why is this omission important? Well, for one it is part of a long series of mistaken statements by many gun-controllers, including President Obama, who made a similar statement in a speech last spring. More generally, the gun control crowd often shows a pronounced ignorance of how guns work and which guns are actually illegal, which certainly doesn’t help when they try to make their case for more strict controls. For just two famous examples, Rep. Carolyn McCarthy (D‑NY) once described a barrel shroud as the “shoulder thing that goes up” (it’s not), and Rep. Diana Degette (D‑CO) once remarked that after high-capacity magazines are emptied they would not be reusable (they are).

It seems reasonable to conclude that, based on the prevalence of these errors by people who should know better, they don’t care too much whether their statements are accurate. To them, the fact that someone used a weapon to commit a mass shooting is enough to ban that weapon. Unfortunately for them, there is nothing about the weapons used in those atrocious crimes that meaningfully distinguishes them from weapons used every day by responsible, law-abiding Americans. The AR-15, for example, used by the shooter at Newtown, is the most popular rifle in the U.S. Ninety-nine point nine percent of the time it is used responsibly, including for self-defense. Ipso facto, it is not just for “spraying death.”

A better argument can be made that actual automatic machine guns “spray death.” And if those are what Justice Stevens believes were used at Newtown, then that seems relevant to his position on guns. I imagine, however, that his views wouldn’t change if he understood the truth. At the very least, however, the Washington Post should make clear that the piece was edited.