Tesla CEO Elon Musk sent an email to factory employees Thursday night calling an employee’s claims regarding working conditions “obviously…untrue”, and the United Auto Workers effort to unionize Tesla’s Fremont factory disingenuous.

In a lengthy Thursday night email to Tesla employees, CEO Elon Musk defended his record as an employer, and appealed to workers not to join the United Auto Workers union.
In the message, first leaked to Electrek.co and later obtained in full by BuzzFeed News, Musk took direct aim at claims made earlier this month in a Medium post by factory worker Jose Moran. Moran alleged that long hours of physical labor once forced six of his eight team members to take medical leave simultaneously. Musk disputed this allegation, claiming a Tesla investigation has proven it to be false. “After looking into this claim, not only was it untrue for this individual’s team, it was untrue for any of the hundreds of teams in the factory,” he wrote.