If you are non-rev'g on a through flight (MEL-SYD-LAX), if it is the same flight number, could you possibly be bumped from 1st class (if you were lucky enough to get it in Melbourne), when you got to Sydney? Would it be only revenue passengers that could possibly bump you or could a non-rev bump you if they had higher priority when boarding in SYD? Thanks for any info. you can provide!