The 3rd Circuit probably wants its decision in U.S. v. Heinrich to be read more by district judges than by lawyers. The district judge “ruled” that the defense could not call a particular expert based on Rule 403. But that “ruling” came from the judge’s law clerk during an off-the-record telephone call in which the district judge did not participate. Moreover, the district judge never actually entered an order or opinion — or did anything else of record.