- An ex-Twitter exec once found Elon Musk's cousin James Musk "basically sobbing," Ben Mezrich said.
- The author of "Breaking Twitter" said James Musk had been worried about being fired.
- James Musk was brought into Twitter after Elon Musk paid $44 billion for the company.
Elon Musk's cousin James Musk was once found on the verge of tears in Twitter's San Francisco headquarters, the author of the new book "Breaking Twitter" said.
Ben Mezrich, who also wrote a book about Facebook that was filmed as "The Social Network," said a former executive of Twitter discovered James Musk in a soundproof phone booth.
Mezrich told Business Insider the former executive described James Musk as "basically sobbing" because he was worried "he would be fired just as easily as anybody else."
"He was in over his head and trying to do what Elon wanted," Mezrich said. "He was overwhelmed and terrified of his own cousin."
James Musk was brought into Twitter, since renamed X, with his brother Andrew Musk a few months after their billionaire cousin paid $44 billion for the company. The brothers are sons of the Tesla CEO's uncle on his father's side.
A person familiar with the matter previously told BI that Andrew Musk worked on software-engineering projects, while James Musk was more of a "fixer type," helping Elon Musk with various tasks.
Representatives for James Musk and Elon Musk did not respond to requests for comment.
Citing unique access to Twitter employees and Musk's confidants, "Breaking Twitter" documents Musk's difficulties since buying the company.
Mezrich describes his book as a true portrayal of the chaotic Twitter takeover, although some dialogue and scenes have been reconstructed. He did not interview Musk for the book.
"Of the scenes in the book, you'll see that it's pretty detailed," he said. "So I have some pretty good sources of people who were in the room for almost everything. The parts of the book where it turns more into sort of speculation are when I'm trying to get inside of Elon's head."
Mezrich previously said that things got so bad for the Tesla CEO that X employees considered calling in a wellness check for the billionaire after he shut himself in his office.