1. Bringing External Law
We've said it before, but it's worth repeating. If the passage says 'Murder is legal', then for that question, murder is legal.
2. Misinterpreting 'Principles'
Read the exceptions carefully. Most questions are based on the 'BUT' or 'UNLESS' part of a legal principle.
3. Over-empathizing with the Victim
Law is objective. Don't choose an answer because it 'feels' fair. Choose it because the principle dictates it.