The American Federation of Teachers made a “panicked” call to Hillary Clinton’s presidential campaign in August 2015, to check on what it considered an alarming rumor, according to an email recently uncovered by WikiLeaks.

The union had heard that Joel Klein, the former New York City School chancellor, was working with the campaign. And it was not pleased.

“Is he joining the campaign in any capacity?” asked Nikki Budzinski, the Clinton campaign’s labor outreach director. “AFT has flagged this as a really big issue for them. I would expect that Randi is going to reach out to John [Podesta, Clinton’s campaign chairman] on this today.”

You can read the whole exchange here.

It turns out that no, Klein wasn’t a campaign aide at the time, said AFT President Randi Weingarten, in a Monday interview.

And she was pretty relieved, she said.

“That’s the kind of rumor we just wanted to track down,” Weingarten said. “Joel may have been incredibly good in Bill Clinton’s Justice Department but he has a toxic reputation when it comes to education.” (Klein also served as an assistant attorney general for Clinton from 1997 to 2000.)

Klein and Weingarten had an especially difficult relationship during the more than half a dozen years he served as chancellor of New York City public schools, and she served as president of the United Federation of Teachers, which represents New York City teachers.

Klein does have some big fans in K-12 policy circles, especially among proponents of education “reform” who credit him with bringing about bold and much needed improvement to the city’s schools through policies like a serious expansion of charters.

WikiLeaks, a group that publishes communications it says point to government and corporate misconduct, recently hacked into emails sent to Podesta, going back to at least 2008.