Right, but there are two paths, so it will actually be in your match in one direction. Anyway, it's not that hard to come up with similar examples where a miss

Right, but there are two paths, so it will actually be in your match in one direction. Anyway, it's not that hard to come up with similar examples where a missing link in the mesh is easier to see than it is to read, and that's my core point. Consider the case of writing out a small connectivity diagram for a near-grid of things. Now everybody but the edge has 4-5 links. One missing in that is brutally hard to find, if it's irregular, but probably still pretty easy to see.