As for the other issue, no bunnies you don't know the question, but thats the easy part. The issue is having the elements and the laws memorised,
Actually, the memorization is considered the easy part at the top schools, which is why they don't bother testing you on your ability to memorize. Hence, open-book. (Frankly, it doesn't make much difference anyway because you end up memorizing most of the stuff just by creating outlines or other study materials. If you're actually looking for the answer to a legal question during the exam, something's gone terribly wrong.)
I agree with this. I find the open book exams to be much more challenging, at least to ace. This is because you basically get no credit for the strict memorization you've done (the easy part of what you're doing when you're studying in law school!). The grades are given based on a curve as everyone here knows, and if all the students have an outline giving them black letter answers, then essentially the entire significant part of your exam grade turns on the depth and quality of your analysis.
I never get how students seem relieved when they find out that an exam will be open note/open book. Maybe if you were the ONLY one allowed to have notes, then it would help you. But since everyone has them, we all just end up canceling each other out on the easiest parts! I was talking to a fellow student about this exact thing earlier today, and we theorized that professors like to go open note because the overall quality of exam probably goes up. Which of course, doesn't benefit students so much as it benefits them. I doubt it has much to do with not wanting to stress us out.