Experts from a US museum believe it could be one of the oldest examples of advanced surgery. The Museum of Osteology in Oklahoma said the skull is reported to have been that of a man who was injured in battle before undergoing surgery to implant a piece of metal in his head to repair a fracture.
Is there more info?
My first thought is why did they discount the idea from movies of someone being executed painfully by having molten metal poured on their head?
Look at the positioning of the metal. Also it heated fusing with the bones.