A guest on a network TV program floats a conspiracy theory so distasteful that the network takes the extraordinary step of publicly rebuking the guest’s comment while vowing never to re-air the program.

It happened last week after commentator Christopher J. Farrell told Fox Business Network host Lou Dobbs that a “Soros-occupied State Department” was funding a large caravan of migrants who are traveling through Latin America on their way to the United States border. His reference was to George Soros, a Jewish billionaire philanthropist and political activist who is frequently the target of far-right, anti-Semitic conspiracy theories.

Farrell’s comment — which has no basis in fact — elicited outrage on social media on Sunday, a day after the mass shooting of 11 people at a Pittsburgh synagogue and less than a week after Soros himself was the target of a bomb scare.

But Farrell isn’t an ordinary TV provocateur. He is a journalism educator at a major university and a member in good standing of two mainstream journalism organizations.

Farrell is an adjunct instructor in the communications department at George Mason University in Fairfax County, Va. According to his department listing, he specializes in “journalism, Transparency & Accountability in Government, Law, National Security.” He also teaches a course in journalism law.

The chairman of George Mason’s communications department, Anne Nicotera, declined to talk about Farrell when contacted on Tuesday. “It’s a personnel matter,” she said, referring a reporter to a university spokesman. She then hung up the phone.

Farrell’s connection to George Mason wasn’t mentioned on Dobbs’s program. Instead, he was identified by his main job: director of investigations for Judicial Watch, a government watchdog organization.

Contacted on Tuesday, Farrell said he had no comment. He referred a reporter to comments made by his boss, Judicial Watch President Tom Fitton, who told The Washington Post in a brief interview on Sunday that Farrell’s comment “isn’t anti-Semitic and Chris isn’t anti-Semitic. To suggest that is absurd. We are concerned about government funding of Mr. Soros, not his religion.”

Fitton didn’t explain the funding to which he was referring or what his concern about it was.

Fox Business said, however, that the outrage over Farrell had some justification. In a statement released on Sunday, the network’s senior vice president of programming, Gary Schreier, said, “We condemn the rhetoric.” He said FBN wouldn’t repeat the Dobbs program, which had already been repeated once.

Fox said it will no longer invite Farrell to appear on Fox Business or the Fox News Channel. It has removed references to the Thursday program from its website and social-media feeds.

Farrell’s TV comments also caused a ripple of controversy at George Mason. A university spokesman, Michael Sandler, said the school had received about a dozen complaints about it, about equally split between people who work at the university and those outside of it. “The general thrust was that they read into the comments that they were anti-Semitic,” he said.

But Sandler called the comments “an issue of academic freedom,” and said no disciplinary action is planned.

“His comments do not reflect the views of the university,” added Sandler. “They are his own. We value inclusivity and diversity. When our faculty speaks to the media, our expectation is that they will elevate the conversation and inform the public. In this case, Mr. Farrell did neither.”

Faculty members at George Mason have begun circulating an “open letter” to the university’s top officials condemning Farrell’s comments. The letter, which had 18 signatures as of Wednesday afternoon, says in part, “While we respect Professor Farrell’s right to speak freely on matters of public concern, we exercise that same right by stating that Professor Farrell does not speak for George Mason University.”

Farrell has been frequently quoted by conservative media outlets on a variety of subjects and has appeared many times on “Lou Dobbs Tonight,” Fox Business’s signature prime-time program.

On Thursday, Dobbs asked him about “leftist groups” that have allegedly organized and financed the migrant caravan, which President Trump and various Fox hosts have referred to as a would-be “invasion” of the United States.

Farrell replied that “a lot of these folks also have affiliates or [are] getting money from the Soros-occupied State Department and that is a great, great concern. We need to start cutting money — start cutting money there.”

He didn’t explain further, and Dobbs let it go without following up.

The comment came two days after police disarmed an apparent bomb sent to a home owned by Soros, part of a wave of suspicious packages sent to prominent Democrats and to CNN. A Florida man, Cesar Sayoc, was arrested on Friday as a suspect.

The Farrell-Dobbs segment aired live without apparent controversy Thursday night, but criticism began after Fox Business re-aired it on Saturday night — several hours after news broke about the massacre of 11 people in Pittsburgh by a gunman spouting anti-Jewish rhetoric.

Farrell remains a member of the Society of Professional Journalists and of Investigative Reporters and Editors, which are composed of working journalists and journalism educators.