Black-letter law snobs
One notorious legend of law school is that law professors don't teach black-letter law, but you're expected to know black-letter law on the exam. "Black-letter" law means pretty much what it sounds like: it's strictly, simply, what the law is. This isn't to say it's one particular theory of statutory interpretation, but rather simply whatever it's generally agreed upon that the law is for some particular subject of the law's purview. Black-letter law is what you can expect to be subjected to in ninety-nine percent of cases, and it's what the bar exam tests.
As to what law professors teach, law students and law students-to-be are terrorized by the commonly prevailing myth that law professors teach something other than what they test. That is to say, they teach their own theories or notions of what the law ought to be/could be, etc., but don't spend much time telling what the law actually says or does. Therefore, students who have kept up fairly well with the reading and taken good notes in class walk, unsuspecting, into the exam to find -- horrors! -- that they're entirely unprepared for what the exam actually tests.
This isn't a fair myth. First, an observation on law professors in general: you don't get to a point in your life where you're entrusted with the education of the next generation of attorneys without it going to your head a little bit. Law professors think they're smart (in most cases, rightly so) and like to hear themselves talk. They also like to hear other people talk like them, because this confirms to them the wisdom of their own observations. What they particularly like to hear is a challenge to their thoughts, followed up by a tidy counterargument that ties the argument together in a way where their opinions are still the prevailing ones. How this translates into exams is, it's probably appropriate to reference just as much black letter law as the professor has herself referenced in class, and then get on to arguing why her opinion is right. Even if you've done a terrible job of studying, she can't help but notice the brilliance of your pointed arguments.
The second, and more serious, observation: law professors, at least the ones I've had, actually do teach what they test on the exam. They teach some varying degree of black-letter law, but it's definitely fair to say that what they don't go over in class, or at least note as important, won't factor heavily into the exam. In fact, one of my favorite professors regularly tells the class before an exam that if we didn't spend much time in class on it, it won't be very important on the exam.
While it is fair to say that some professors are more interested than others in teaching black-letter law -- and some subjects, such as civil procedure and evidence, lend themselves to a more black-letter law-heavy class -- the fact is, law school just isn't going to teach you what you need to know on the bar exam, so it's best to simply worry about the exams, which generally aren't so attenuated from the actual content of the class. Still, some students insist on criticizing professors who are less concerned about delving into the minute details of the black-letter law. For instance, another one of my favorite professors is often critized for not teaching enough black-letter law, but instead directing his class to more theoretical and abstract legal problems. Having majored in philosophy and political science in college, I personally like this approach, but the students who have it drilled into them that the only thing that matters is the black-letter law seem almost to enjoy turning up their noses at professors like this one. This professor is almost certainly aware of this trend among the student body, and so the last day of class he came into the room and wrote a few things on the board before beginning the class:
"Okay, case A held B. Case C held D. Case E held F. Case G held H. Now onto the interesting stuff."
Good thing I got my friend's notes. That went really fast.
I suppose I should stop procrastinating and get back to outlining Criminal Procedure now.