James Damore, the former Google engineer who was fired Monday after posting a missive criticizing the company’s diversity programs, offended fellow Harvard graduate students with an off-color skit during a 2012 retreat, prompting two professors to send an email apologizing for the performance.

At the time, Damore was a doctoral student in systems biology. Along with a few dozen other students and faculty, he attended a two-day retreat at a hotel in Portsmouth, New Hampshire, that included discussions about science as well as a dinner followed by students performing in skits that typically poke fun at professors.

According to accounts of the event from three people who attended and one person familiar with the skit, Damore performed as professor Timothy Mitchison, who discovered a concept initially called “Microtubule Jerking." Damore, portraying Mitchison, used suggestive phrases to thank women who had helped with the "jerking" discovery.

“The delivery was just awful,” the student tells WIRED. “It’s a room full of scientists so there’s a lot of awkwardness, but this was especially awkward. Maybe told in a different way it would have been received as a joke.” A second person who attended the event does not remember the specifics involving Mitchison. But the second student recalls that Damore’s performance “crossed the line. It seemed inappropriate and I remembered a portion of the community asking him to apologize.” The third classmate, a female, tells WIRED that jokes in the skits usually roast colleagues, but typically the focus is on professors, not students. “He was a kind person whose misguided attempt to be funny failed,” she says. “I think that he wanted the skit to be a chance for him to be funny and cool, but overdid it.”

After the event, which was first reported by Gizmodo, Mitchison and Andrew Murray, the codirectors of the program, emailed the department to apologize. “Even in the context of a deliberately humorous event, targeting any group within the program that can be defined by gender, by ethnicity, by sexual orientation, or by religious affiliation, is never acceptable,” the professors wrote, according to a copy of the email reviewed by WIRED.