I just called bonds unicresity. According to them, all the three components including ATAR, psychometric testing and interview are weighed equally.
Did you speak to someone from Medicine admissions specifically? From their website:
"Step One - Academic Assessment
Students will be assessed on their prior academic record through their application on QTAC. Approximately 50% of applicants will be invited to complete Step 2 (ETA: Psychometric Test) of the admissions process.
Step Two - Psychometric Test
The results of the psychometric test will determine eligibility for being offered an interview as the next step of the assessment process...
Step Three - Interview
..."
It would seem weird for them not to use ATAR/GPA as part of the interview decision making process, but then to bring it back in for offers, as they'd have a whole heap of applicants with ATAR/GPA on the low end who would find it very difficult to compete.
Also, it's still possible for that statement to be technically correct if you think Psychometric testing eligibility is 100% based on ATAR/GPA, Interview eligibility is 100% based on psychometric test, Offer is 100% based on interview performance.
ETA: the use of the headings "Step One", "Step Two", etc, also suggests to me that the academic assessment has already taken place in step one, it doesn't happen again in step 3.