Retaliation/wrongful demotion?

Sam has worked between 44 and 50 hours each week. Regardless of how many hours he works, he's paid $3000 per month. He questioned his supervisor about this and was told that he is not entitled to overtime pay because he is an administrative employee. Sam took the next step of filing a complaint with the Department of Labor. At a meeting where this case was discussed by a group of managers and the company attorney, the HR mananger stated that she believed the company was violating the law and should pay Mr. Maxwell the overtime that he is owed. Several of the other managers took exception to her comments and asked her whose side she was on. She was demoted to the secretarial pool several days later. A company VP stated that, based on her comments at the meeting, the company had "lost confidence in her ability to serve as a member of the management team." Shortly after she quit and is now suing. Is it correct that the company was wrong in retaliating against her and demoting her?