That is also likely a QC issue.
CGC slabs a lot of books.
As Vintagecomics keeps reiterating, ANY glue on a post-1950 book, regardless of perceived intent, is an automatic PLOD. Same goes with colour touch. Any SA book with "small amount of colour touch" on the label in a blue label has also slipped past QC (I have seen a handful of those as well).
-J.
I agree with this. This is also what I know to my knowledge regarding SA books and color touch/glue = automatic purple. GA on the other hand is different. To me, it seems like CGC was aware when they typed in the small amount of glue on a blue label SA book. Just dunno how this is different from any other SA books with glue or color touch on it.