Don't mean to dig up an old thread but the same thing happened to someone at my school last year, was near top in business but ended up with a terrible HSC mark. Paid BOS, and found they didn't mark a section, when it got marked got an extra 10 in his HSC external score, most of the small cohort increased marks by 0-1 lol. this is probably more common than people think I guess.
THANK YOU GUYS FOR ALL YOUR HELP!!!
Board of studies contacted me this morning saying they're getting the booklet marked, and hopefully, will get a new hsc mark by tmrw or thursday!
and they will contact UAC for a new ATAR