This, I think: https://apnews.com/article/elton-john-testifies-for-defense-kevin-spacey-sexual-assault-trial-68c1108bd46e5641bc10d0a5b3ccc785

Short version: the defense brought Elton and his husband to testify that Spacey wasn’t at the ball where one of the alleged attacks happened.

I don’t think testifing to factual matters (prossibly under subpoena) equates “defending,” but what do I know?