Asked why Depp fired her, Jacobs said: "I really don't know. All I know is that he terminated essentially everyone in his life."
Depp's lawyers have put experts on the stand who testified that the actor lost millions because of the domestic abuse accusations, including a $22.5-million payday for a sixth installment of "Pirates."
Depp filed the defamation complaint in the United States after losing a separate libel case in London in November 2020 that he brought against The Sun for calling him a "wife-beater."
Depp, a three-time Oscar nominee, and Heard met in 2009 on the set of "The Rum Diary" and were married in February 2015. Their divorce was finalized two years later.
Judge Penney Azcarate has scheduled closing arguments in the case for May 27, after which it will go to the jury.