Twitter has lost its top content moderation official just weeks before the company is set to undergo a regulatory stress test by European Union officials focused on its handling of user content, in the latest sign of turbulence at the company under owner Elon Musk.

On Thursday, Twitter's head of trust and safety, Ella Irwin, told Reuters she had left the company. Irwin has not addressed the reasons for her departure, but the move coincided with the company's content moderation dispute with the Daily Wire, a conservative outlet.

The dispute focused on the forthcoming release of a self-described documentary, "What Is a Woman?" that Twitter warned would be labeled as "hateful content" due to two instances of misgendering, according to Daily Wire CEO Jeremy Boreing. Musk intervened later Thursday, calling the content moderation decision "a mistake by many people at Twitter" and that the video would be "definitely allowed."

Twitter did not immediately respond to a request for comment on Irwin's departure.

But the sudden and unexpected vacancy at Twitter could leave the company without a key content moderation official at a sensitive moment. Later this month at Twitter's San Francisco offices, EU officials are set to review whether the platform is likely to be compliant with a sweeping content moderation law that could eventually trigger millions of dollars in fines for Twitter if it's found to be noncompliant.

That law, known as the Digital Services Act, will require so-called "very large online platforms" including Twitter to abide by tough content moderation standards by as early as August. It's far from clear whether the company can meet those requirements by the deadline, and recent developments at Twitter seem to have further alarmed EU regulators in that respect.

For months, as Musk has increasingly welcomed more incendiary speech onto the platform Twitter had previously restricted, EU officials have been reminding Twitter of its content moderation obligations under the DSA. The warnings have also come amid mass layoffs at the company that have eliminated entire teams, including much of its content moderation staff.

Last month, Twitter pulled out of the European Union's code of conduct on disinformation, a series of voluntary commitments to combat mis- and disinformation that the EU has said would be considered as part of any evaluation of a platform's compliance with the overall Digital Services Act (DSA).

Although Twitter said it was "committed to fully complying with the Digital Services Act" and would meet its DSA obligations with respect to misinformation "in a manner that reflects Twitter's unique service," the company told EU officials "we feel we have no alternative" but to withdraw from the code.

The announcement prompted swift backlash from Thierry Breton, a top EU commissioner and digital regulator, who appeared to regard Twitter's decision as an attempt to evade responsibility.

"Obligations remain," Breton said. "You can run but you can't hide."

Irwin's departure could undercut the EU's confidence further. Without a trust and safety head who would otherwise be expected to attend the EU stress test, Twitter's ability to effectively respond to the evaluation may be constrained. A spokesperson for the European Commission didn't immediately respond to a request for comment.

All of this could be problematic for Twitter and Musk in the long run -- and could also create an added headache for Linda Yaccarino just as she takes over as the company's new CEO.

Companies that fail to abide by the DSA risk fines of up to 6% of their global annual revenue. For Twitter, which is already struggling to regain its financial footing amid significant debt and an advertiser backlash, that's a cost it can ill afford.