Elon Musk can use whistleblower claims from Twitter’s former head of security, Pieter Zatko, as he attempts to get out of the $44 billion acquisition, a judge has ruled. The ruling comes one day after lawyers for Musk and twitter faced off in Delaware’s Court of Chancery over Zatko’s allegations.

Twitter had argued that Zatko was a disgruntled employee, and that Musk was looking for reasons to get out of the deal long before he learned about the whistleblower complaint. The decision could complicate Twitter’s ongoing legal battle. The company has so far declined to address Zatko’s allegations in detail, though it’s not clear how long it can continue to do so. Zatko is also scheduled to testify at the Senate Judiciary Committee next week.

Musk’s attempt to delay the October trial that will decide whether he can get out of the Twitter deal, however, was rebuffed. In the same decision, the judge wrote that “even four weeks’ delay would risk further harm to Twitter too great to justify.” The trial is scheduled for October 17th and expected to last 5 days.