For the "what if you don't get into med this year" question at an interview, I would honestly go to UQ if I can't get into med elsewhere, unless I somehow totally bomb out and don't scrape a 95 (99 with bonus points) needed at UQ. Is it even wise to mention UQ specifically (not even in my home state)?
Or are the interviewers looking for what I'd do if I don't get into UQ?
I believe I answered this above, but to make this clearer - if they ask what you would do if you didn't get into medicine, if you couldn't start your answer with 'If I didn't get into medicine I would' then it doesn't answer the question. For example, 'If I didn't get into medicine I would do medicine at UQ' makes zero sense as an answer.
As stated above, you are allowed to be honest and say you have an offer elsewhere, but I'd also want to see your thought process as to if medicine fell through, where are your interests, motivations, and career interests?