In more complex cases, diagnosis is as much art as science. There aren't always evidence-based clinical practice guidelines to follow so clinicians often have to rely on experience and intuition. Subjective judgement is a factor.
Under HIPAA, patients do have the legal right to correct errors in their medical records.
they do, culturally. However, data does influence their decisions. Appropriately diagnosis are probability based and is an art. Its not perfect, but currently it is good