Yes, but only because history is in a constant state of revision.
Timothy Messer-Kruse is an Expert with a capital E on the matter of the Haymarket affair, one of the most important events in American labor history. Heck, Mr. Messer-Kruse has even written a well-regarded book on the resulting trial of eight men, seven of whom were sentenced to death (and four of whom were executed). He has, by his own account, spent years trying to find out what happened during that trial, and, in particular, answer the question of why it lasted for six weeks if, as is commonly understood, the prosecution "did not offer evidence connecting any of the defendants with the bombing," to quote an earlier draft of history from Wikipedia.
In the course of his research, Messer-Kruse found that this was "flatly wrong." He took to Wikipedia to correct the passage, but his edits were denied by the Wikipedia gatekeepers. As Messer-Kruse explains in The Chronicle of Higher Education:
One hundred and eighteen witnesses were called to testify, many of them unindicted co-conspirators who detailed secret meetings where plans to attack police stations were mapped out, coded messages were placed in radical newspapers, and bombs were assembled in one of the defendants' rooms.
In what was one of the first uses of forensic chemistry in an American courtroom, the city's foremost chemists showed that the metallurgical profile of a bomb found in one of the anarchists' homes was unlike any commercial metal but was similar in composition to a piece of shrapnel cut from the body of a slain police officer. So overwhelming was the evidence against one of the defendants that his lawyers even admitted that their client spent the afternoon before the Haymarket rally building bombs, arguing that he was acting in self-defense.
So I removed the line about there being "no evidence" and provided a full explanation in Wikipedia's behind-the-scenes editing log. Within minutes my changes were reversed.
The problem? Wikipedia's "undue weight" policy, which says that "articles should not give minority views as much or as detailed a description as more popular views." This is an important policy, one that guides Wikipedia non-expert volunteers in weighing the edits of a minority view. And often, in many debates about history -- particularly one that has relevance to today's partisans -- one expert can vehemently disagree with other experts. Telling the difference between a personal hobby horse and a legitimate inaccuracy is not just a matter of rote fact-checking, but of judgment. Wikipedia's undue weight policy is a way of using scholarly consensus to pass those judgments.