Well, personal information in medical records, let's say, would be the contents of my file, the medical details about me: my state of health, the results of my latest tests, things like these. This is all personal information related to me.
In the case where the Privacy Commissioner decided that some alleged personal information was in fact a work product, as I remember it had to with the prescribing patterns of doctors. So it wasn't personally about the doctor--himself or herself--like the contents of my medical file would be about me. Rather, it was the information about the doctor displayed through his or her professional activity.