The Court of Appeals for the Tenth Circuit recently held that an expert”?s testimony did not go far enough. In Kirkbride v. Terex, USA, LLC, 378 F.3d. 1343 (10th Cir. 2015) plaintiff was assisting in the repair of a rock crushing machine. He was attempting to dislodge a foreign object from the machine when suddenly it was expelled striking him in the neck and jaw. He alleged that a toggle plate in the machine was defective. The jury awarded him 3.5 million dollars.
When the machine encounters uncrushable material, it is the toggle plate”?s job to break and prevent a pressure build-up. The plate in question failed to break and when measured, it was found to be 3/16 of an inch thicker than the design specification. Plaintiff claimed that if the toggle plate had been manufactured properly it would have broken and the accident would not have occurred.
Plaintiff”?s expert simply testified without calculations, testing, or other application of scientific methodology that a thicker plate is obviously more difficult to break than a thinner one. He said he did not need any testing as a mechanical engineer to know that, if something is too thick, it is more difficult to break. He did not testify when a properly manufactured plate would break and the court found that it was clear from the record that he had no opinion on that subject. The court said “without expert testimony that a non-defective plate would have broken,” the jury could only speculate that a manufacturing defect was the cause of the plate”?s failure to break. Since a jury findings of causation cannot be based on speculation, the court reversed and remanded.