Obviously things were more complicated that they have been portrayed, and there is not enough information in the public domain to understand what was happening.
No doubt Craig Jurisevic was qualified to be an independent cardiothoracic surgeon. He had passed his exams and gained his fellowship. That does not automatically qualify him for accreditation to any particular private hospital.
Clearly Ross and Knight did not approve of his entry into private practise (at whichever hospital they worked at). Whether their reasons were financial, altruistic, or otherwise I do not know.
Perhaps they were asked their opinion by the Hospital's accreditation committee and they gave it honestly. Perhaps they actively tried to block his accreditation by portraying Jurisevic dishonestly. Perhaps what they did or did not say didn't matter, and the hospital itself would have made an independent decision about Jurisevic's accreditation based on other factors.
In any case, the ACCC saw the outcome and Ross and Knight's actions as stifling competition. That's why they prosecuted and succeeded.
Nevertheless, in a small, saturated or mature market, qualities such as overseas experience may be desirable. And if, in effect, the ACCC is saying that private hospitals must approve accreditation to everyone who applies (without regard to their other qualities, or lack thereof), then this is a big deal.
Let us say, for example, that Surgeon X has a reputation for poor results, or creating staff conflict, but is an otherwise qualified surgeon in his specialty. Do other surgeons in his specialty have the right to prevent his appointment in order to maintain quality or harmony at that private hospital? (NOTE: I am not implying anything about Craig Jurisevic here)
Does the hospital have a right to refuse accreditation on these "soft" criteria?
Would things have been different if Knight and Ross had threatened to withdraw services if Jurisevic were appointed, rather than saying that he was not qualified? The hospital has a reputation to protect, and not appointing a singular new surgeon in order to keep the business of two other surgeons would be merely a commercial decision.
Maybe the hospital felt that it had enough CT surgeons, and would not accredit another one unless they were "outstanding"?
Perhaps things are skewed because cardiac surgeons are a service profession (unlike most other specialties), and there are only a limited number of hospitals with coronary pump facilities. Maybe if your career is under the thumb of a cardiologist it makes you do weird things.
I'm sure Craig is a smart man, and has plenty of options to further his career. The ACCC's action was presumably to benefit Adelaide residents by maximising their access to cardiac surgical services. It was all about what Ross and Knight did, and little or nothing to do with Craig Jurisevic or his personal interests.
As for overseas or post-fellowship experience being desirable - there would be no issue if Craig's appointment to a public hospital were declined due to Ross and Knight's actions. A public hospital has every right to set it's standards as high as it likes before appointing another surgeon. As far as I am aware, a public hospital is not involved in a commercial marketplace, and therefore the ACCC and the Trade Practices Act has no jurisdiction.
But the rules for a Private Hospital are different - Craig Jurisevic did not miss out on a job, he missed out on a right to enter a competitive market for surgical services at that hospital. I wonder if the ACCC's win means that private hospitals will be compelled to maximise competition within their own walls. We might start sueing each other over whether our names appear more prominently around the hospital, as it may stifle business and competition. What a world.