Lawyers for Elon Musk are asking a federal judge in Los Angeles to toss the defamation lawsuit filed against the tech CEO by Vernon Unsworth, the British caver whom Musk called a “pedo guy” on Twitter in the wake of the rescue of a youth soccer team from a cave in Thailand last year.

Musk lashed out at Unsworth on social media last July after both volunteered as part of the rescue of 12 Thai boys and their soccer coach from a flooded cave last July. The caver gave a critical interview to CNN claiming that a submersible tube Musk and his team of engineers designed was a “PR stunt” prior to Musk’s since-deleted Tweet calling him a “pedo guy.”