That's just stupid. The LSAT is hugely correlated with 1l grades.
Honestly, please, no one listen to this guy.
Yes, of the individual quantitative measures currently used, the LSAT is the most predictive (although there are some other hybrid measures, such as UGPA combined with LSAT scores that seem to work a little better).
However, that does not mean IL grades and LSAT scores are "hugely" correlated. Anyone with a background in statistics/psychometrics who has taken the time to actually look at LSAC's data critically will see that the supposed correlation is fairly weak.
Also, as others have pointed out, there are massive methodological issues associated with studies that seek to establish such correlations, the most glaring of which, at least to my way of thinking, being the weakness or absence of control groups in most IL classes (this is especially the case when evaluating classes at top schools).
Look, I'm not saying that the LSAT is useless as a tool. Far from that. I am merely attempting to prevent this discussion from drifting too far from reality based reality.
The test is the single most important factor in determining ones chances of being admitted to a given law school, and should therefore be taken very seriously. However, constantly trumpeting the test's wonderful predictive powers, as you do Judge, serves only to mystify the LSAT, and that does a disservice to those people who come to this board seeking advice on how to approach it.
I didn't say it was wonderfully predictive. It does have some glaring problems. For example, it overpredicts black 1L performance by a margin of about 5 test points. IE the black who scores a 160 (and because of AA will get into schools as if he was white and had a 170) will, on average, perform at the level of a 155 taker.