I disagree with that part --- I was doing composition for my elective and for extension, and I don't believe it's fair for me to be marked harsher simply because I am more advanced at the theory component (albeit I still came second in the performance aspect too thanks to playing the piano for a while, but that's a different matter).
Music 1 and Music 2 are different courses with different focuses - one is aimed at modern music (media music, film music, rock, pop, etc.), while the latter is focused on historical music (medieval, baroque, classical, romantic, etc.). As such I believe the marking should be the same - too bad marker's can't stop themselves from being biased