Do you have an HR department? if so, you can report it to HR.
or, you can fish and see if any other employee noticed the same and may be get their opinion.
On the other hand, while it would bug me, I am not sure if I would choose to spend my energy on it. It is their supervisor's responsibility to catch that false reporting.
The thing is that it is difficult for me to provide an insight because I don't know your work environment, culture and the laws surrounding the business.
For instance if I had experienced your situation at my old job, I could feel comfortable enough to report to HR knowing that it would be handled in a classy and a fair way. However, I would not even bother reporting it at my current job because it is very toxic environment and it is possible that somehow I would end up getting in trouble for it.
So, in summary, in a well functioning company you could report it to HR (in confidence) and move on with your life. However, in a corrupt environment, things can work to your disadvantage.