Justin Baldoni’s former publicist, Stephanie Jones, is hitting back at his claims that she leaked confidential information as part of an effort to defame Blake Lively.

In dual filings Thursday night in U.S. District Court in New York, attorneys for Jones say she produced the sensitive material not as a voluntary act of subterfuge, but in response to a subpoena. A story in the New York Times about the tangle behind the scenes of the film, set off a media frenzy by drawing on some of that information, which included text messages from principal figures.

Baldoni and Lively, co-stars in the hit 2024 film It Ends With Us, have been engaged in a multi-front legal battle in recent months. While the film was a left-field commercial smash, its production and marketing formed the core of an interconnected and explosive set of legal claims between members of both camps. The...