"Hubbuch says he shouldn't have been fired because, at the Post's insistence, he deleted the tweet later the same day he posted it and posted other tweets apologizing for it. That's an ethical argument, not a legal one. The boss can decide when sorry just won't cut it."

Hubbuch refers throughout his complaint to his "tweeting hobby" that got him fired, but that's a real stretch. Hubbuch's offending tweet wasn't hobby activity; it was political activity. Anyway, is it really credible for a sportswriter who used Twitter to engage his readers, and who, according to his complaint, previously was called on the carpet by his superiors for sports-related tweets, now to label his tweets just a hobby? The difficulty of separating the work person from the private person is not always easy for anyone.

Significantly, Hubbuch couldn't and doesn't rely on the part of the law that prohibits termination for "political activities." That is because the only political activities covered by the law are running for office, campaigning for a candidate, or participating in political fund-raising.

Second, other reasons Hubbuch says made his termination wrongful didn't make it illegal. Like the vast majority of private sector employees, Hubbuch was employed at-will. That meant the Post could fire him for any reason that was not specifically against the law. Hubbuch contends that his firing "betrayed the Post's core belief that people should not be punished for expressing unwelcome personal views on their own." So what? Even if the allegation is true, an at-will employer may fire someone for a reason that is at odds with its stated mission as long as it is not at odds with stated law.

It also doesn't matter that the Post allegedly had no written policy that applied to Hubbuch's use of social media. An at-will employer is not limited to firing people only for breaking written, or even unwritten, rules.

Hubbuch further says he was really fired because Rupert Murdoch, the chairman of the Post, wanted to stay on Donald Trump's good side because the President now has the power to benefit or harm Murdoch's business interests. This is an especially odd contention because the very New York law on which Hubbuch relies specifically does not protect off-duty activity that creates a material conflict of interest with the employer's business interests. The inflammatory tweet of a prominent sportswriter would seem to pose a material conflict with the Post's business interests for precisely the reason Hubbuch gives in his complaint.

Third and finally, Hubbuch says he shouldn't have been fired because, at the Post's insistence, he deleted the tweet later the same day he posted it and posted other tweets apologizing for it. That's an ethical argument, not a legal one. The boss can decide when sorry just won't cut it.

The lesson here for anyone in any industry and any state is that everyone can see public posts on social media. That "everyone" includes your boss. Impulsive social media posts may get a person elected — or fired. Tweet carefully.

Commentary by Dan Eaton, a partner with the San Diego law firm of Seltzer Caplan McMahon Vitek, where his practice focuses on defending and advising employers. He also is a professor at the San Diego State University College of Business Administration where he teaches classes in business ethics and employment law. Follow him on Twitter @DanEatonlaw.

For more insight from CNBC contributors, follow @CNBCopinion on Twitter.



