So yes, I highly recommend that people should get a copy of their file, and be prepared to find it highly upsetting.
Did that a while back with my file at CentreLink (the main Australian government welfare agency). Included in that file was the compulsory psych report required for my disability pension application. Naturally, the psych was chosen by CentreLink, so I am pretty sure he was not too unsympathetic to their wants.
The experience of the psych interview, and the contents of the resulting report, were a real eye opener.
Both the interview and report were quite clearly incompetent and dishonest, and deliberately designed for one purpose, to discredit me and deny the claim,
irrespective of its legitimacy.
That was 25 years ago. I regret to say that the overall situation for patients does not seem to have improved much since then.
(In fairness to CentreLink, my application was ultimately successful, so the psych's 'evidence' was not taken too seriously. Might have been something to do with the fact that the evidence from the professor of immunology who diagnosed me did not support the psych's view.)
It is an interesting thought that a main piece of evidence against the psychs might come from the discrepancy between what they tell patients in the clinic, and what they say about them in the clinical notes and medico-legal reports.