Emma Sulkowicz, the infamous "mattress girl," surfaced this week on National Public Radio talking about her efforts to get a serial predator, "a sadist in the truest meaning of that word," off the Columbia University campus.

Sulkowicz, referred to in the story as an "activist and survivor," mentioned that the subject of her efforts won a settlement from Columbia this month in a lawsuit charging that Sulkowicz's activism amounted to gender-based harassment.

When a disciplinary hearing in late 2013 cleared Paul Nungesser of charges that he raped Sulkowicz, she refused to accept the outcome. Her protest—which included carrying a mattress on campus for most of her senior year to represent the "weight" of her victimization—made her the heroine of a new feminist revolution. It also made him the campus pariah after she outed him as her alleged rapist.

While the terms of the settlement are unknown, Columbia issued a statement effectively reaffirming Nungesser's exoneration. This was an important victory not just for Nungesser and his family, but for those who have argued the war on campus rape, however worthy its goals, has often trampled on the innocent.

It is a timely victory, given the current controversy over possible shifts in federal policy to ensure more protections for the accused.

As the first journalist to fully report Nungesser's side of the story with important exculpatory evidence, I consider it something of a vindication as well—after such reactions as a piece on the feminist site Jezebel titled "How to Make an Accused Rapist Look Good."

When I first read the front-page story on Sulkowicz in the New York Times in May 2014, I actually believed—despite having criticized the excesses of the college rape crackdown—that she was probably a victim wronged by campus bureaucrats.

There were no "blurred lines" of consent here. Sulkowicz described a brutal assault by a (then-anonymous) friend and occasional sexual partner who, she said, suddenly turned violent during a consensual encounter, hitting her, choking her, and anally raping her while she screamed in pain.

According to Sulkowicz, the man was found "not responsible" after a botched investigation and remained enrolled at the university, even though he had been accused of sexual assault by two other female students as well.

The facts grew considerably murkier when I read an earlier report on the case in Bwog, Columbia's online student magazine.

The multiple complaints, it turned out, were not independent of each other, and the other two women were not alleging rape. One was an ex-girlfriend who had "felt emotionally and sexually exploited" by the accused, though she did not recognize it as abuse at the time; she and Sulkowicz both decided to file complaints after sharing their experiences. The other one said he grabbed her and tried to kiss her at a party when they went upstairs to get more beer—an incident that she admitted she didn't regard as assault until she learned about the other charges.

In late December 2014, long after "mattress girl" had become a national icon, The New York Times published a story that included an interview with Nungesser (who had been named by The Columbia Daily Spectator in May). What piqued my interest was his contention that "he was not allowed to bring up communications between himself and Ms. Sulkowicz after the night in question" in his defense. Oddly, nothing was said in the story about the content of those communications.

About a month later, I met with Nungesser for an interview on the Columbia campus in upper Manhattan. His parents, Karin Nungesser and Andreas Probosch, who live in Germany, had contacted me after reading my articles on campus rape controversies and after I mentioned my interest in the case on Twitter.

Among the materials he gave me were several pages of Facebook messages, which later figured extensively in the lawsuit. They show that for weeks after he supposedly raped her on August 27, 2012, Sulkowicz had affectionate chats with Nungesser, sending him such comments as "i feel like we need to have some real time where we can talk about life and thingz" (sic) and responding to his birthday greeting with "I love you Paul!"

After I wrote about this in the Daily Beast, Sulkowicz supporters argued that "survivors of trauma deal with their experiences in different ways" and that she was being faulted for not being a "perfect victim." "To anyone who has been close to a person who has been the victim of acquaintance rape, Emma's messages to Paul don't seem out of the ordinary," wrote Erin Gloria Ryan at Jezebel, which also published Sulkowicz's annotated copy of the messages.

Victims of violence can indeed respond to trauma in ways that seem irrational. But it's the specifics that strain credulity. Sulkowicz was not alleging a "gray area" situation that she could have excused as a misunderstanding; she claimed she was hit in the face and choked so hard that "he could have strangled me to death." Yet we are asked to believe that two days after this attack, both victim and rapist would banter as if nothing was wrong; that she would come to his party and respond to his request to bring more girls with "i'll be over w da females soon"; and that "I want to see yoyououoyou" means (as Sulkowicz claimed in her Jezebel annotations) she was "desperate" to talk about the rape.

The annotations also contained a surprising claim from Sulkowicz: that a few hours after the assault, she talked to a female friend "who explain[ed] it was rape." Would that really need explaining? And why was there no record of this friend being called as a corroborating witness?

Eventually, I got an answer which adds a minor but fascinating detail to the story, reported here for the first time. A source familiar with the case confirmed that in her original complaint, Sulkowicz mentioned talking to a friend, "Toni" (not her real name), the day after the incident.

Investigators interviewed Toni, but she was not called to testify, the source said; all she could say was that Sulkowicz had told her she felt weird about what had happened between her and Nungesser.

My attempts to reach Toni were unsuccessful. But I found out from her online profiles that during her time at Columbia she was both a social justice activist and a sexual assault peer counselor. It's entirely possible that Toni asked Sulkowicz whether her experience might have been nonconsensual. But if she is indeed the mystery friend, her activism makes it even more remarkable that she did not corroborate Sulkowicz's claim of rape or publicly support her.

Based on all the known facts, I think Sulkowicz's version of the events is extremely unlikely. Was she a vengeful scorned woman, as the Nungesser lawsuit suggests? I don't know. I think Sulkowicz genuinely believes Nungesser did something abusive to her that night, whether or not that belief has any relation to reality. But there is also strong evidence that "mattress girl" has been knowingly dishonest.

In a May 15, 2014, Time essay titled "My Rapist Is Still on Campus," Sulkowicz wrote, "Every day, I am afraid to leave my room." Yet a New York magazine web story on May 18 quotes her as knowing her alleged rapist "is out of the country." (Nungesser was spending a semester in Prague. He is now back in his native Germany, where he works in film.)

No one knows for certain whether Nungesser is innocent of all wrongdoing. But the multiple charges from multiple people add up to remarkably little. As I reported here two years ago, the conclusions of Columbia's internal investigation of another complaint, brought by a male student in late 2014, more or less openly suggested it may have been part of a collective vendetta by friends of Sulkowicz—indirectly validating Nungesser's claims of collusion.

Nungesser's lawsuit, particularly its second version filed last year after the first complaint was dismissed, makes a strong case that he experienced egregious harassment at Columbia, abetted by school officials who approved Sulkowicz's "mattress performance" as her senior art thesis.

In the summer of 2014, other students and a professor pressured Nungesser to drop out of a scholarship-paid class trip to Russia, Mongolia, and China. That October, on a "Day of Action" against sexual assault, several mattress-toting activists showed up in one of his classes, where they stared at him and took his picture. Keyboard warriors in the social media urged making his life "a living hell" and sometimes called for violent retaliation.

In a January interview, Sulkowicz denied engaging in "a bullying campaign" against Nungesser, saying that "no one knew his name until he put it out there." That is, to put it bluntly, a lie.

Months before Nungesser spoke to the media, Sulkowicz explicitly said that she had filed a police report mainly because "his name should be in the public record." She cited as her inspiration a Brown University student who named-and-shamed her alleged assailant out of school when he returned from a suspension. And she criticized Columbia administrators for removing the "rapist lists," with Nungesser's name at the top, that had appeared as bathroom graffiti in some dorms.

Throughout Sulkowicz's crusade, Columbia coddled her and acted as if Nungesser's exoneration was an embarrassing faux pas. His parents' pleas for a statement that the school stood by the results of its disciplinary process were ignored.

To have such a statement now is a satisfying outcome for the parents. Nonetheless, Karin Nungesser told me by email that they would have liked to see the lawsuit go forward, if only to get access to Columbia's records on the case. (She thinks, contrary to Sulkowicz's claims, the investigation was "very much designed to prove Paul guilty.")

A feminist journalist, Karin Nungesser also believes advocacy for the wrongly accused is part of the fight for gender justice. "In a way, this is similar to victims of sexual assault," she says. "The public has to understand that false accusations are not a triviality—they exist and they destroy the lives of those affected. It really doesn't matter whether 2% or 8% of sexual violence accusations are false. We have to accept that false accusations exist and learn how to deal with them. But this will only be possible if victims of false accusations are able to tell their story publicly."

Tell that to NPR, which still calls Sulkowicz a "survivor." Or to the campus sexual assault activists who still refer to Paul Nungesser as "Sulkowicz's rapist."