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Judge: ex-lab director can sue accuser for defamation

Plaintiff resigned position amidst sexual harassment scandal

Pat Murphy//November 20, 2025//

Test tubes in research lab

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Judge: ex-lab director can sue accuser for defamation

Plaintiff resigned position amidst sexual harassment scandal

Pat Murphy//November 20, 2025//

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In brief

  • Judge allows ex-lab director’s claims against a subordinate to proceed.
  • Whitehead Institute and its director win summary judgment on gender bias claims.
  • Statements labeling plaintiff a “rapist” and “predator” deemed potentially actionable.
  • Court recognizes disputed over nature of parties’ relationship.

The former head of a laboratory at a Cambridge biomedical research institute could proceed with defamation claims against a subordinate who accused him of sexual harassment, a Suffolk Superior Court judge has ruled in partially denying defense motions for summary judgment.

Plaintiff Dr. David Sabatini resigned his position at the Whitehead Institute for Biomedical Research in 2021 after an independent investigation by the law firm Hinckley Allen concluded he had violated the institute’s sexual harassment policy. The conclusions of the investigation were based in part on Dr. Kristin A. Knouse’s allegations that she had had a long term, nonconsensual romantic relationship with Sabatini.

Sabatini later sued Knouse for defamation. Knouse moved for summary judgment, contending the alleged defamatory statements attributed to her — which included statements made to Knouse’s Whitehead colleagues and friends as well as Whitehead administrators and Hinckley Allen investigators — were either conditionally privileged or nonactionable personal opinion.

Business Litigation Session concluded that statements expressing the defendant’s subjective feelings about the plaintiff’s conduct — such as the fact that she felt “abused” by the relationship — were expressions of personal opinion not susceptible to proof as either true or false and, therefore, not actionable.

However, the judge found actionable the defendant’s statements that the plaintiff was a “rapist” who had “assaulted” her, statements that he was a “dangerous predator” who “grooms” the subordinate women in his lab, and statements that likened the plaintiff to Harvey Weinstein and Jeffrey Epstein.

Barry-Smith wrote that the latter category of statements “reasonably could be understood to state as a matter of provable truth or falsity that based on Knouse’s personal knowledge of Sabatini and their relationship, he committed some level of sexual crime against her (rape and/or assault), and has a history of sexually harassing the subordinate women in his lab. Where the consensual nature of Knouse’s and Sabatini’s sexual relationship is highly disputed, no more is required to overcome a motion for summary judgment.”

The judge likewise found a jury issue existed as to the plaintiff’s claim that the defendant tortiously interfered with prospective employment opportunities.

On the other hand, the judge found the Whitehead Institute and Whitehead Director Dr. Ruth Lehmann were entitled to summary judgment on the plaintiff’s claim that those defendants had engaged in gender discrimination in violation G.L.c. 151B by orchestrating a biased investigation against him.

The 25-page decision is Sabatini v. Knouse, et al., Lawyers Weekly No. 09-153-25.

Looking forward to trial

Knouse is represented by Boston attorney Ellen J. Zucker.

“We are, in fact, heartened that over the course of multiple rulings the court has rejected the unmoored conspiracy theories that fueled Sabatini’s claims, generally,” she said. “We are also glad that the Whitehead Institute, which did the right thing by thoroughly investigating the concerns expressed by multiple women, now will no longer face litigation for actually investigating inappropriate conduct on the part of one of their ‘stars.’”

Zucker further credited the trial court for “dramatically narrowing” the claims against the defendant.

Ellen J. ZuckerWe are, in fact, heartened that over the course of multiple rulings the court has rejected the unmoored conspiracy theories that fueled [the plaintiff’s] claims, generally.

— Ellen J. Zucker, Boston

“[The judge’s] decision itself expresses skepticism about what remains,” she said. “In this context, we look forwarded to presenting her case to the jury.”

Zucker noted that, earlier in the case, the trial court had dismissed the defendant’s counterclaim against the plaintiff for sexual harassment under G.L. c. 214, §1C. The SJC has since taken up the case on further appellate review after the Appeals Court affirmed the lower court’s ruling. The justices have solicited amicus briefs on a single question: “Whether a claim under G. L. c. 214, §1C, for sexual harassment in the educational context must be brought against the educational institution and not against an individual.”

Oral argument in that case is anticipated early next year.

The plaintiff’s attorney, Edward F. Foye, declined a request for an interview. In response to a request for comment, the Boston attorney wrote in an email, “[W]e will appeal the judge’s decision on our case against the Whitehead Institute in due course and look forward to trying the case against Dr. Knouse for defamation and interference with advantageous relations.”

Counsel for defendants Whitehead Institute and Dr. Ruth Lehmann did not respond to a request for comment.

Boston employment attorney John F. Tocci recently represented a client in a case raising issues similar to the ones raised in Sabatini. Tocci defended City of Boston employee Hilani Morales in a defamation suit brought by former city health director Felix G. Arroyo. Arroyo accused Morales of defaming him in making allegations of sexual harassment. In June, Tocci obtained a defense verdict in favor of his client after a two-week jury trial in Suffolk Superior Court.

“The law of sexual harassment is designed to protect statements made by accusers and victims of sexual harassment and those who come forward with a complaint of harassment and also those who cooperate in the investigation,” Tocci said. “All of those statements are and should be protected.”

Tocci commended Barry-Smith for distinguishing opinion from statements of fact in ruling on the plaintiff’s defamation claim.

“There are some judges who ‘miss the boat’ on that distinction, but the judge here was spot on in construing a number of [the defendant’s] statements as opinion or, as he called it, ‘florid language, rhetorical hyperbole and insults,’” Tocci said.

According to Tocci, one key to the summary judgment in favor of the Whitehead defendants was that the institute engaged an outside investigator to investigate the culture in the plaintiff’s lab.

“It gave the investigation the imprimatur of legitimacy and objectivity,” he said.

Alicia J. Samolis chairs the labor and employment practice group at Partridge, Snow & Hahn. The Providence attorney said that what stands out to her as a defense attorney is the fact that the plaintiff’s defamation claim survived summary judgment.

Alicia J. SamolisFrom an equitable point of view, I don’t believe it is a necessarily bad decision to say, ‘Look, you at least need to go to a jury on this if you are going to choose to couch your accusations like this knowing that in the technical sense they are not true.’

— Alicia J. Samolis, Providence

“Typically in these cases, it’s very hard for someone who has been accused of doing something like harassment to sue the other side for anything,” she said. “Usually in the defamation context, you have several barriers, including the litigation privilege, conditional privilege or [the statements in dispute constitute] opinion. The opinion exception to defamation is very broad.”

But Samolis said she can understand the court’s decision to allow the plaintiff’s defamation claim to go forward based on the defendant’s alleged statements regarding rape and other misconduct.

“From an equitable point of view, I don’t believe it is a necessarily bad decision to say, ‘Look, you at least need to go to a jury on this if you are going to choose to couch your accusations like this knowing that in the technical sense they are not true,’” she said.

Sexual harassment investigation

Whitehead is a non-profit research institute, affiliated with the Massachusetts Institute of Technology. Whitehead receives funding from the Howard Hughes Medical Institute.

According to court records, the plaintiff became a faculty member in the MIT biology department in 2002 and that same year was appointed a Whitehead member, where he operated his own lab. In 2008, he also became an employee of HHMI after accepting a position as an investigator.

In 2017, the plaintiff assumed an executive role at Whitehead as an associate director, and in 2018 Whitehead appointed him as director of the institute’s fellowship program.

Knouse began a joint M.D./Ph.D. program at Harvard and MIT in 2010. In 2012, she met the plaintiff during her graduate studies at MIT. In 2017, the defendant became a Whitehead fellow with the support of the plaintiff. Later, the plaintiff became her mentor in the fellowship program.

In 2016, the defendant began socializing with the plaintiff and the members of his lab. In April 2018, the plaintiff and the defendant began a sexual relationship and over the next several years had multiple sexual encounters. They dispute whether the sexual relationship was consensual and whether the defendant felt pressured, coerced, or forced into the relationship, which ended in early 2020.

In January 2021, two former members of the Sabatini lab complained to Whitehead about the plaintiff.

In March 2021, a consultant hired by Whitehead to conduct a diversity, equity and inclusion survey reported that the Sabatini lab had been identified as fostering a sexualized culture.

In late March 2021, Whitehead hired Hinckley Allen to conduct an investigation. During that investigation, the defendant disclosed her sexual relationship with the plaintiff, who when questioned by investigators initially denied the relationship. He later conceded that it had existed.

The law firm issued a report on the results of its investigation in August 2021. In that report, the firm concluded that the plaintiff was not credible and had violated Whitehead’s directive not to interfere in the investigation.

Sabatini v. Knouse, et al.

THE ISSUE: Can the former head of a laboratory at a biomedical research institute proceed with defamation claims against a subordinate who accused him of sexual harassment?

DECISION: Yes (Suffolk Superior Court, Business Litigation Session)

LAWYERS: Edward F. Foye, Arrowood LLP, Boston (plaintiff)

Ellen J. Zucker, Zucker Law Group, Boston (defendant Dr. Kristin A. Knouse)

Kay H. Hodge, Stoneman, Chandler & Miller, Boston (defendants Whitehead Institute for Biomedical Research and Dr. Ruth Lehmann)

Moreover, the firm reported its conclusions that the plaintiff had: (1) violated Whitehead’s sexual harassment policy by engaging in sexist and sexualized discussions with lab members; and (2) leveraged his status to facilitate a secret sexual relationship with an individual later identified to be the defendant in violation of Whitehead’s consensual sexual and romantic relationships policy, which prohibits “consensual sexual or romantic relationships between co-workers … with unequal power or authority between the individuals.”

The plaintiff received a copy of the report on Aug. 19, 2021, and resigned the following day. On the same day he resigned from Whitehead, HHMI informed him that he was being terminated for cause.

The plaintiff sued Knouse and the Whitehead defendants in October 2021. His lawsuit included claims against the former for defamation, tortious interference with prospective business relations, intentional and negligent infliction of emotional distress and hostile environment sexual harassment in violation of G.L.c. 151B.

In addition, the plaintiff sued Whitehead and Lehmann for gender discrimination.

Jury issues

Knouse argued that she was entitled to summary judgment on the plaintiff’s defamation claims insofar as they related to her statements to Whitehead executives and Hinckley Allen investigators because such statements were conditionally privileged.

But Barry-Smith observed that she would lose the conditional privilege that attached to those statements to the extent that she acted out of malice, knew her statements to be false or acted with reckless disregard for the truth.

“Given the extent of Knouse’s publications, and her clear hostility toward Sabatini as evidenced by her stated intent to have him ‘fired and also publicly outted so that he can’t get a job anywhere,’ and where the truth or falsity of her statements are within her personal knowledge and are in dispute, resolution of this issue remains for the fact finder,” the judge wrote.

However, the judge granted Knouse’s motion for summary judgment on the plaintiff’s emotional distress claims related to statements made outside the scope of Knouse’s employment. As to those claims, the judge found the plaintiff was unable to point to evidence that Knouse made those statements with an intent to cause him emotional distress or that she acted in a negligent manner.

The judge further dismissed as untimely the plaintiff’s hostile work environment claims against Knouse.

Regarding the plaintiff’s claim of gender discrimination against Whitehead and Lehmann, the judge found the results of Hinckley Allen’s investigation undercut his allegation of discriminatory animus.

“On these facts, while certainly not perfect, … the Investigation was no sham,” the judge wrote. “It gathered sufficient evidence to allow Lehmann and Whitehead to draw an independent conclusion that Sabatini had violated Whitehead policies based on his own admitted conduct and contemporaneous documentary evidence. Sabatini does not argue, or establish through the record, that a different or better investigation would change these essential facts.”

Lawyers Weekly No. 09-153-25

Massachusetts Lawyers Weekly

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