Any vert that is on the outer edge of the brick will be pushed out slightly so that it overlaps with adjacent bricks. If it didn't do this then you would see sparkly holes between bricks at a distance.
Well, for that part of the brick in particular, it would not be required since it will never stem to bricks adjacent to it, don't suppose you could provide the offset value that is being done upon doing so when attempting to make bricks like this?, that way we can apply the offset value to the piece coming off, it will match up with the other pole bricks perfectly, and so on.