Oh wow, that's interesting. I've actually read the opposite—that the LSAT score is usually a better indicator of how well a student does in law school than GPA or other factors. I wonder where their data is from.
I also wonder. But the data about LSAT being a better indicator is from LSAC, who might, just might, have a vested interest in the LSAT being a valid predictor.
LSAC threatened banning any school that uses other standardized tests from using their data base. Articles about his can be found on Above the Law. Monopolies tend to be very protective of their territories.