Law decided by precedent is no law at all, it is tyranny piled upon tyranny.
I have repeatedly stated that our legal system takes what is considered to be a couple of fallacies (Fallacy of Authority, and fallacy of Tu Quoque) and turns them into a methodology. Precedent is the notion that because some "authority" decided a case a certain way for one litigant, similar cases must always therefore be decided the same way, regardless whether the "precedent" decision was correct or not. Flaws are built right into the legal system, and they are proud of the fact!
Science and Engineering requires that arguments be built from "first principles" and not rely on the unproven pronouncements of other Scientists or Engineers. I sometimes suspect it would be doing the world a service to eradicate all the legal case books so lawyers and judges could only reference the laws themselves, and not be persuaded by previous judges doing their thinking for them.