Really? No underlying facts at all? Never? Is anyone else surprised about the outcome of Lighting Ballast?
I am. I thought there would be some—though maybe negligible—situation where the district court was forced to rely on extrinsic evidence, such as expert testimony. And the district court’s decision with respect to that evidence would be reviewed for clear error.
Sure, it would be a rare situation where the construction of a patent claim term actually turned on the court’s decision on this extrinsic information. But nonetheless, haven’t we all seen this rare situation at least once?