It seems that the nickname "Iron-Faced Judge" is somewhat common in wulin. In DGSD, there was an "Iron-Faced Judge" who was a figure in the mass coverup regarding the origins of Kiu Fung, and in LUK SIU FUNG, there was a character called "Iron-Faced Judge" who was a lackey of Fok Yau's Green Shirts Pavilion. I think another "Iron-Faced Judge" or two might have also shown up in other wuxia stories.
Were there many judges moonlighting as wuxia warriors, and did a number of them claim the nickname "Iron-Faced Judge?"