After Tesla this week objected to a regional National Labor Relations Board ruling that it violated federal labor laws and engaged in anti-union activity, the case goes to the NLRB in Washington, D.C.

The Palo Alto company filed 166 exceptions to a September decision by Amita Baman Tracy, an NLRB administrative law judge in California.

The judge found that Tesla interfered with labor union organizing in 2017 and 2018, and ordered that CEO Elon Musk be present while a notice is read to the compay’s workers explaining their rights. She also ordered the company to reinstate an employee, Richard Ortiz, who had alleged he was fired for pro-union activity.

Tesla maintains in its filings that Ortiz was fired for lying during an investigation and not for, among other things, asking the company for information about workplace safety records.

A lawyer for Ortiz has not returned a request for comment.

Also included in the case is a tweet by Musk — who recently was found not liable in a defamation lawsuit over a tweet in which he called someone a “pedo” — that the judge found to have been a threat to take away Tesla workers’ stock options if they unionized.

Last year, Musk tweeted the following: “Nothing stopping Tesla team at our car plant from voting union. Could do so tmrw if they wanted. But why pay union dues & give up stock options for nothing? Our safety record is 2X better than when plant was UAW & everybody already gets healthcare.”

In one of two filings dated Dec. 9, Tesla said, “Exception is taken to the (judge’s) failure to find that the nature of Twitter should be considered in weighing the legality of Musk’s and Tesla’s tweets.” The company also objected to the judge’s finding that Musk’s tweet constituted workplace conduct and invoked Musk’s First Amendment rights.

A spokesman for the United Auto Workers, which is a charging party in the consolidated case, said Thursday the union could not comment on a pending case.