Yes, you cannot be fired for legally protected reasons. Well, the company that fired you also knows that. So they come up with a reason that is not protected(

Yes, you cannot be fired for legally protected reasons. Well, the company that fired you also knows that. So they come up with a reason that is not protected( "Does not fit well with the company culture"). The burden of proof is upon the ex-employee to show that they were let go for a protected reason(It is a very high burden).