They probably didn’t miss it. The concept is PCGS graders probably didn’t think it was bad enough to rate a “details” grade. We can disagree with that. PCGS may have seen this as an MS-64 with an “L”. I saw the same thing with a 1798 Bust Dollar that had the sharpness of an AU with two letters lightly scratched into the right field. It was graded EF-45. My question is, why did CAC approve of that? Wasn’t CAC created to approve coins that were solid for the grade?
CAC approved AU53, likely original surfaces, the grade is right but this picture is the best possible - in hand it is dull, dark gray color.