So they were given the SAC as a practice and given the exact same one for the actual SAC?
Some points:
* If they were legitimately given the SAC by the teacher (or found the SAC online etc) and it matched what they were actually given, it is not the student's fault so they can't be blamed. If anything, the responsibility re: this lies with the teacher not the student to comply with VCAA guidelines.
* The only time that this student could be penalised would be if they obtained the SAC by illegal means e.g. hacking teacher's laptop, collecting off their desk in a staff only area (and even if this was true, the teacher has to ensure SACs are kept secure) etc.
* I find it quite strange that items were included in the SAC that weren't in the study design. Are you sure this is the case? If so, you may contact somebody at the school with your concerns.
and an extension question that most people were unable to complete.
Eh, this part is common. Extension questions are just that, extension. They aren't designed for everybody to get full marks for. This is definitely allowed.
In a general sense, schools and teachers are responsible for ensuring that the company/commercial SACs they use aren't repeated, meet the study design requirements for the current year etc. So.. unfortunately in your case the student is not at fault unless again, they obtained via illegal means. If you want to direct any sort of blame, your teacher would be a good place to start for allowing it to be used without checking.
tl;dr :
- student not to blame if teacher recycled SAC / used commercial without checking. Exception to this is if they illegally obtained a copy before the actual SAC.
- responsibility lies with the teacher/school to comply with VCAA guidelines for SACs.