upper tribunal hearing - pip

i am writing for a friend. Her family member is once again pursuing a downgrading of a pip award. It was indicated to my friend that the family member needed to produce medical records. But the family member will produce a consultant's report who is an expert on the family member's condition. My friend argues that this is a fishing expedition. is there any precedents or rules of evidence that support my friend's argument? Where can she find resources about upper tribunal decisions and regulations? The family is representing themselves.

FYI the judge at our previous first tier tribunal recommended, recorded in the written judgement, that claimant's medical records be submitted in future. Crazy waste of NHS time and paper but have duly got them in case needed as suggested this time, can't argue with a judge. Even if they have completely ignored written request for a longer award on the basis of inherited conditions where effect on all descriptors will only worsen with time. Though at least they restored Enhanced x 2. Good luck.
Denby