The general counsel of the ACLU testified Thursday in the Johnny Depp-Amber Heard trial in Virginia that the foundation believed billionaire Elon Musk was behind a $500,000 payment to help the actress fulfill a $3.5 million donation pledge to the organization.

Heard had said she would donate $7 million from her divorce settlement with Depp to charity, split between the ACLU and Children’s Hospital of Los Angeles.

But in Depp’s $50 million defamation claim against Heard, his attorneys have been trying to show that Heard has not followed through on the pledge to the ACLU.

Excerpts from a video deposition of the organization’s general counsel, Terence Dougherty, were played in court on Thursday, and he said that the organization has so far received $1.3 million that has been credited to Heard.