The marking process is just the beginning and they have the HSC to do at the same time.
After all the exams are marked the aligning process has to be finished.
This is where they adjust the raw exam marks to the scaled marks that you get. This process won't begin for SC until part way through the marking process and will finish a week or so afterwards but... the BOS only spends two days in consultation with the various judging panels to finalise these aligned marks. These two days are in early December and will entail all HSC and SC courses over the same two days. One consultation committee might go from SC History to HSC Japanese and then onto 2U Maths before morning tea and so on.
Some HSC subjects have already finished being marked (Geography, Chemistry and Modern History that I know about) but their judging panels haven't finished their work and the SC judging panels won't finish their job until late next week I believe. Some HSC subjects are just beginning the marking process and won't be finished for another two weeks and then they have to finish the judging process before the consultation committees meet.
The Consultation committees ask the judges about how they reached their determination for the cut-offs for the bands and then the committee decides whether to go with the panel's recommendation or not (and the panel isn't told - or at least we weren't told when I was on the judging panel a few years ago - it was one of our complaints that we did all that work and then never got told the result).
The Consultation meetings are usually late in the first week in December and then all the marks have to go into the computers and the results printed. Printing 80,000 results sheets for each SC subject (you get a separate sheet for English, Maths, Science, History, Geography and Computers) plus the actual certificate, which can't be done until all the necessary requirements of the certificate have been met (i.e. after checking students have either done the exams or satisfactorily explained why they didn't do so) takes time - a couple of days at least. Then they have to be put into envelopes and sent to schools. Some of the reason for the delay is simply the sheer number of candidates and the amount of paper required to be sent to each student.