Ah, now I understand your question. To my eye, I don’t see any cells in which the intersection of two cells actually defines a nodal point for the adjacent face. More simply, it doesn’t look like having two cells along a face actually splits the adjacent face, so all hexahedrons are still hexahedrons.
EDIT
And then I found a picture that invalidates the above, so I’m out. Regardless it still looks like shared faces = adjacency.
