What is going on after interview a s before final offer.

Hi everyone, I applied for a job through SA Careers and had my interview a while back. After that they contacted both of my referees.

I’ve now received an email saying they’re in the final stages of the process, that approval is being sought, and that shortlisted candidates will be contacted soon.

So, my question is,

Is there usually another assessment after the interview? The words “shortlisted candidates” confused me, since I thought the shortlist was the interview stage.

One of my referees was the co-supervisor for my master’s thesis here in Australia, and I’m a bit worried she may not have spoken positively about me. My other referee gave a good word for me. Does it matter much if one referee doesn’t respond positively ?

Any insight would be appreciated. Thanks.