If Mark Halperin’s sexual harassment was an “open secret,” his writing partner John Heilemann says he was never let in on it. Speaking for the first time on Halperin’s fall, Heilemann says the allegations left him “flabbergasted and shocked” when his nine-year partner called to tell him about the upcoming CNN exposé. Heilemann tells the New York Times’ Michael Grynbaum that their partnership is over, but Heilemann knows that questions still remain:

In the interview, Mr. Heilemann said he was still coming to terms with the accusations that have been lodged against his longtime collaborator. Mr. Halperin — who has denied allegations of groping and assault, but acknowledged pursuing relationships with ABC colleagues — worked at ABC until 2007, roughly a year before he teamed up with Mr. Heilemann for “Game Change” during the 2008 presidential campaign.

“The bare nature of the accusations are horrific and shocking and terrible,” Mr. Heilemann said. “These behaviors are not the behaviors that I witnessed, and they’re not consistent with the person that I thought I knew. That’s not an excuse. That’s just the truth.” …

“I had never heard of, been exposed to or had any inkling of the notion that he had engaged in any behavior that could be described in even the broadest sense of being sexual harassment or sexual assault,” Mr. Heilemann said, in his first public remarks since the claims against Mr. Halperin surfaced.

Heilemann knows that questions will be raised about his knowledge of Halperin’s behavior, after having worked so closely with him on a number of joint projects. They spent a lot of time on the road covering the 2008 and 2012 elections, writing two best-sellers together. They also partnered on Showtime’s The Circus, traveling the country to serialize the 2016 election, and worked together for Bloomberg News.

Surely all that time together would have revealed something about Halperin, right? Heilemann says he never saw any indication at all of behavior issues, which he chalks up to Halperin’s explanation that he cleaned up his act after leaving ABC, well before their partnership began. “The timeline is what the timeline is,” Heilemann tells Grynbaum, although at least two newer allegations of harassment have emerged, both from 2011, well into Halperin’s partnership with Heilemann. Both took place on college campuses, not at political events, and Heilemann wouldn’t have been present, but these hint that Helperin’s timeline might not be the timeline.

Heilemann’s claims of total surprise might well be true, but that might also indicate that his antennae aren’t very well tuned. Recall that the Daily Beast reported from “numerous sources” — including at Bloomberg, the Heilemann-Halperin base of operations — that Halperin’s behavior was indeed well known:

According to numerous sources at NBC, MSNBC, ABC, and Bloomberg—who previously spoke to The Daily Beast on the condition of anonymity in order to speak freely—the private allegations of Halperin’s sexual misconduct were an open secret, particularly in New York City and D.C. political media, for many years.

People just didn’t feel emboldened to talk or speak out, in part due to Halperin’s position of power in the industry.

“Everybody knew [about Mark],” one prominent cable-news host told The Daily Beast. “I’d been warning young women reporters about Mark for a long time.”

That reporting also plays hob with the claim that “the timeline is what the timeline is.” Perhaps Heilemann didn’t get told because he was too close to Halperin, but if this reporting is accurate, Heilemann didn’t pay much attention to his surroundings. That’s not exactly a confidence booster in his work.

“I hope that my reputation has not been damaged by this,” Heilemann tells Grynbaum. It’s far from destroyed, but it’s impossible for any of Halperin’s close associates to come out of this without some damage.