SpaceX head, Elon Musk, appeared in court in Los Angeles for his troublesome tweets in a defamation case, Time reported.

He was to explain what he meant when he called Vernon Unsworth, who helped rescue youth soccer players trapped underwater in a Thailand cave, “pedo guy” in a Twitter spat more than year ago.

“‘Pedo guy’ was a common insult used in South Africa when I was growing up,” Musk said in a court declaration. “It is synonymous with ‘creepy old man’ and is used to insult a person’s appearance and demeanor.”

Unsworth participated in a large-scale operation to save 12 children and a trainer from a flooded cave in Thailand in June 2018. He discovered their whereabouts in the cave and assembled a team that managed to save them. Musk and his SpaceX company sent a small submarine of their own device to Thailand and sent to help divers.

Musk later apologized for his tweet after the diver belittled Musk’s efforts to build a tiny submarine to save the trapped boys as a “PR stunt.”