Question asks you to draw a labelled diagram for a galvanic cell, it's worth 2 marks. You need correct anode, cathode (labelled as such with correct material identified), external wire with voltmeter and electron flow labelled, polarity of each electrode, solution, labelled salt bridge with labelled ion flow, showing how oxidised atoms move off the anode and how reduced atoms move to the cathode. You miss anything, you lose a mark. You miss two things, no matter how small, you get zero marks for the question. That's how our trial was marked in one question based off an 06/07 question.
If that's the basis of how they mark it, does it really surprise you?
Yeah I had some wtf moments during looking at the marking of my chem trial. One question was out of 5 and they gave me 1.5/5. Looking at the marking scheme it looked like at least 4/5, but everyone's was marked really weirdly for that so I didn't bother arguing it.