Judge Jack Weinstein is ordinarily pretty lenient when it comes to whether expert witnesses satisfy the Daubert standards for testifying.

Yesterday, however, he excluded an expert in the Zyprexa MDL on Daubert grounds.

(Don’t get us wrong here. Judge Weinstein also denied motions to exclude two experts yesterday. But we’re choosing to focus on the rarer bird — the exclusion.)

In In re Zyprexa Prods. Liab. Litig., No. 04-MD-1596, slip op. (E.D.N.Y. May 12, 2009) (link here), plaintiffs offered Stephen J. Hamburger, M.D., to prove the specific causal relationship between the Zyprexa ingested by particular plaintiffs and the onset or worsening of their diabetes. Hamburger had been deposed in 20 cases, and the court held an evidentiary hearing, so the evidentiary record was pretty extensive.

Judge Weinstein found that Dr. Hamburger met “the necessary educational and experiential qualifications warranting admissibility of his expert testimony.” Id. at 8. And Hamburger’s opinion on general causation was sufficiently reliable. Id.

But his specific causation opinions were unscientific. Here’s the money quote:

“He has been shockingly careless about the facts in the cases he proposes to opine about: whether weight gain preceded or followed use of Zyprexa, whether there was weight gain at all, the scientific basis for the claimed causal link between Zyprexa intake and medical injury, and the like. Faced under oath with consistent extensive factual discrepancies in his analyses, he merely shrugged them off or flippantly shifted to new theories and explanations to establish causal relationships. He repeatedly and impermissibly stretched the truth to support findings of causality.

“Dr. Hamburger’s pattern of disregard of facts and theory mandate his rejection as an expert in all these cases. The court cannot permit a major pharmaceutical litigation to become the subject of the kind of ‘rubber-stamp’ expert opinions that have so marred mass litigations such as those involving asbestos and breast implants.”

Id. at 9.

Kudos to Andy Rogoff and his team at Pepper Hamilton for the win.