Removing slab results in sculpted terrain

So… This gets weirder…
Apparently if you delete the road as shown in the first attachment in the original post it replaces the road with regular dirt as normal, but also changes the road occupying the same place as the structure to dirt.

And furthermore it generates more dirt blocks to occupy all blocks of the structure even if the road was not occupying that space. The structure in that image is a simple standing wall I built to cover where i mined to much and there was no dirt when i built it there, and there is now dirt occupying all spaces of that structure. This is further evidenced by removing one of the walls as shown below.

As you can see the only wall now occupying that space is surrounded and encased in dirt. This is reproducible with both stone and dirt.
So yea, fun bug.

Steps to reproduce:

  1. Mine out an entire chunk from the ground.
  2. Place a structure that occupies an entire wall of the chunk. 4x5x1
  3. Build a road on top of the ground to include the structure. Observe first bug.
  4. After completion delete the road. Dirt and structure should occupy each other entirely.
  5. Delete structure and dirt should occupy the space the structure previously should.