Tesla CEO Elon Musk apologized for making an unfounded claim last week that one of the divers who played an instrumental role in rescuing the Thai soccer team from a flooded cave was a pedophile.

In a series of tweets Tuesday, the tech billionaire said his comment calling British caver Vern Unsworth a “pedo guy” was “spoken in anger,” Musk wrote.

“His actions against me do not justify my actions against him, and for that I apologize to Mr. Unsworth and to the companies I represent as leader. The fault is mine and mine alone.”

The apology follows Unsworth’s remarks saying that he wouldn’t rule out legal action after Musk publicly accused him of being a pedophile.

Musk’s derogatory tweet was part of a spat between him and Unsworth. In an interview with CNN on Friday, the cave explorer said that the mini-submarine Musk sent to aid the rescue mission was just “a PR stunt.” Unsworth also said Musk could “stick his submarine where it hurts,” and that it had “absolutely no chance of working.”

Read More: What’s Going on With Elon Musk? How the Happy Billionaire Rocket Scientist Became a Cautionary Tale

Musk received major backlash for his comments, and Tesla shares tumbled on Monday because of his remarks. In an open letter on Tuesday, Tesla investors called on Musk to apologize.

Get The Brief. Sign up to receive the top stories you need to know right now. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Contact us at letters@time.com.