Tesla Wins Challenge to NLRB Decision on Musk Union Tweet (1)

Tesla Inc. prevailed in its second bid to overturn an NLRB decision that company CEO Elon Musk’s tweet saying workers would lose stock options if they unionized was an illegal threat under federal labor law.

The 9-8 decision Friday from an en banc panel of US Court of Appeals for the Fifth Circuit delivers a blow to the National Labor Relations Board’s authority to enforce labor law’s prohibitions on employers’ coercive anti-union statements, particularly when they appear on social media.

A three-judge Fifth Circuit panel last year upheld the NLRB’s decision finding that the offending tweet violated the National Labor ...