my friend used to work for the unemployment office and she handled the cases and decided if people got it or not. oh the stories she would tell me!!
and don't piss off your case worker, they will deny you for being an idiot.
Not sure that your friend should really be telling you this kind of stuff since it's probably confidential (and frowned upon to deny someone unemployment because the caseworker doesn't like them)!
But, like the other posters have said, anyone who thinks they are being unfairly terminated should document, both for unemployment compensation purposes, as well as if the employee wants to bring litigation in the future. It is much easier to prove a case when you have documentation to support your claims, as you may be able to use that documentation to negate an employer's claim that the termination was for performance reasons.