A fired employee can sue for wrongful dismissal. If this happened to your check with a lawyer, if you can show that the company had a pattern of overlooking such things, then you can get big bucks in court.
I know of people who should have been fired who were talked into quitting instead just because quitting means they can't sue. In turn the company gives the official answer "X worked here between these dates and left in good standing". Since the company always said the same thing when asked if someone worked there it wasn't a negative to the next employer, while if they fired they would have to say left in bad standing.
Of course since getting fired is a sensitive issue I won't say who. Reading between the lines in conversations and how the company acted though I'm sure that is how it worked.
Any company that states that an employee left "in bad standing" either has an idiot for counsel, or poor HR practices. Providing any information other than employment dates opens you up for lawsuits.
Which is why the company works hard to convince someone who should be fired to quit. If they fire someone and don't mention that fact they can be sued for withholding information, but if the person quit on their own terms.
Note that there is a difference between being sued and losing in court. Even if you win you still need to pay your lawyers. I've had one lawyer tell me about spending nearly a million dollars in court for a case that was about $100,000 in asked damages that the lawyer knew based on facts they would lose - but [I can't talk about this part] made it impossible to figure out how to settle out of court.
I know of people who should have been fired who were talked into quitting instead just because quitting means they can't sue. In turn the company gives the official answer "X worked here between these dates and left in good standing". Since the company always said the same thing when asked if someone worked there it wasn't a negative to the next employer, while if they fired they would have to say left in bad standing.
Of course since getting fired is a sensitive issue I won't say who. Reading between the lines in conversations and how the company acted though I'm sure that is how it worked.