Sorry, but neither of these are true.
The way the marks are aligned depends on the Performance Band Descriptors for each course. A team of judges, who are drawn from the HSC marking team for each subject, determine what raw mark on the exam paper corresponds with the borderline of each of the performance bands.
It is all covered on the Board's website:
http://www.boardofstudies.nsw.edu.au/yourhsc/step8-judges-apply-the-standards.html.
Scaling based on quality of the candidature is done by UAC in determining each student's ATAR, which is completely separate to the Board of Studies and aligning of examination marks.