Consider the alternative where employers can fire you for lying about your employment history. Once you’ve done some union organizing, you’d be potentially unhireable.
ETA: Here's the relevant part of the judicial decision in this case:
> None of these employees [who were fired for lying and used to claim precedent in this case] are an appropriate comparator for McClure, who was never accused of stealing, violating traffic laws, or other criminal conduct. And, even if Respondent could show that the other employees were fired just for lying, and not for the underlying serious misconduct, Respondent could not use that to justify firing McClure because they were all accused of lying about conduct that Respondent could lawfully consider in hiring or firing them. In contrast, McClure lied about his history of working for union employers. Because Respondent could not refuse to hire McClure because of his union background, his lie about working for Deem can’t be used to justify firing him.
ETA: Here's the relevant part of the judicial decision in this case:
> None of these employees [who were fired for lying and used to claim precedent in this case] are an appropriate comparator for McClure, who was never accused of stealing, violating traffic laws, or other criminal conduct. And, even if Respondent could show that the other employees were fired just for lying, and not for the underlying serious misconduct, Respondent could not use that to justify firing McClure because they were all accused of lying about conduct that Respondent could lawfully consider in hiring or firing them. In contrast, McClure lied about his history of working for union employers. Because Respondent could not refuse to hire McClure because of his union background, his lie about working for Deem can’t be used to justify firing him.