Less than three weeks ago (it seems a lot longer) we posted about the FDA’s position that expert witnesses shouldn’t be allowed to opine on the meaning of FDA regulations during trial. Such opinions, the Agency argued, were legal – not factual – opinions. Thus they were the province of the court to decide, and then to instruct the jury.
We’ve just learned of another appellate court reaching just the same conclusion. In Caputo v. United States, 517 F.3d 935 (7th Cir. 2008) (copy here), the court stated:

The district judge did not abuse his discretion — the right standard, see General Electric Co. v. Joiner, 522 U.S. 136 (1997) — in keeping out of evidence the proposed “expert” testimony that defendants wanted to introduce. The “expert” would have testified about the meaning of the statute and regulations. That’s a subject for the court, not for testimonial experts. See Bammerlin v. Navistar International Transportation Corp., 30 F.3d 898, 900 (7th Cir. 1994). The only legal expert in a federal courtroom is the judge.

Caputo, slip op. at 12. This is, to our knowledge, the first federal appellate ruling excluding an “FDA expert” on the ground that the proffered opinions were improper legal conclusions.