HOMEWhen positive performance reviews can help with termination
In the post on whether positive reviews will legally protect you from layoffs and firings, we said that, generally, the situation is such that even if you have a history of excellent appraisals, your employer will probably be able to fire you anyway.
We also mentioned there were a few situations so we'll cover them there. There are actually two possible sets of circumstances where your positive reviews can help.
Firings Possibly Motivated By Racism, Gender Discrimination, or Similar Contexts
While employers have free reign in most employment decisions, there are specific laws that forbid DISCRIMINATION on the basis of race, gender, etc. These laws can differ by country, state and province, although they tend to be similar or identical in different areas of ONE country.
If you end up filing a complaint against your employer because you believe you have been unlawfully discriminated against, the company may respond by saying you were a poor performer, and suggest that's why you were fired. If your reviews have been solid or excellent, the court could form the belief that your employer is not credible, and side with you.
In other words if your company claims something and your performance reviews provide evidence that refutes the company's claim, that' may help you, but please see the disclaimer.
When You Have A Specific Contract
The second situation can occur when you have signed a contract (usually one that you negotiate), that spells out the rights of both you and the employer, and provides the conditions under which you may be terminated. This situation is actually not an employment law one, but one of contract law. (Torts).
If you your contract is terminated unlawfully (i.e. they've broken the conditions of the contract by terminating you), and if they claim they've done so for performance problems, the documentation and reviews you may have that disprove their allegations can be telling in a court of law (or not, again read the disclaimer).