I worked for GM as a salaried chemist. My manager was on maternity leave so her boss was my acting manager for a year.
He lied in the written mid-year review he submitted, which he told me nothing about.
I complained to HR about the inaccuracies when I finally saw them at the end of year. HR investigated. Poorly. They decided they would not correct my review or instate the raise and bonus I should have gotten.
During the investigation I submitted a letter to HR detailing this manager's problematic behaviors. The letter included the fact that he had lied on other employee's reviews. It also included multiple instances of sexual harassment.
I had spoken with my colleagues that had him as a manager and they were willing to stand with me and provide HR their experiences.
The HR manager did not investigate. So I emailed the HR executive. He did not do anything.
How do I know?
The next year, this manager was promoted to level 9, which is as high as you can get without being an executive or VP.
As far as I know, he is still gainfully employed and headed towards retirement with a pension and 401k, despite my pending legal action for related issues.