I would assume either gaps or overhangs that are greater than the stitch tolerance. Geometry Inspector won't find them because they aren't faults. You may be able to use the Intersect, Trim, or Extend commands to fix this if that is the issue.
show non-stitched surfaces will give you a quick look at the areas that still need attention.
I will give that a try....I can't find any obvious either overlapped or unstitched edges....but will check more closely.