To the OP:
Even though you're not 1st, the fact that the gap is small (~ 1 mark) means that you shouldn't be adversely affected by the moderating process. Whatever the situation, the smaller the gap between you and the person in front, the better.
In terms of the process in general:
Yes, the person ranked first internally always gets the highest exam mark as their assessment mark. Note, however, that they may not necessarily get the highest HSC mark seeing as every student retains their own exam mark and the HSC mark is the average of the exam mark and the internal mark.
Person A could rank #1 and get 75 in the HSC exam. Person B, ranked 2nd and 1 mark behind Person A, might top his/her class with a 99 in the HSC exam. Even though Person A will have an internal assessment mark of 99, when you average the exam mark and the assessment mark, Person B will most likely end up with the highest HSC mark.