Witness tampering allegations are something U.S. District Judge Ed Kinkeade of Dallas has seen a lot in criminal cases, but never before in a civil lawsuit in his court.

That may help explain why the Dallas judge took strong action on Oct. 16 and told lawyers in a hip implant bellwether trial that he would have the FBI and the U.S. Attorney’s office question a New York doctor and others about a conversation the doctor had just a few days before he was scheduled to testify at the trial.